Got it. I’ll investigate the risks of EMP (electromagnetic pulse) attacks to the United States—both nuclear and non-nuclear—focusing on congressional discussions, military assessments, and infrastructure resilience. I’ll look into historical and recent measures taken to harden infrastructure, including both civilian and military systems, and highlight what, if anything, is likely to survive such an attack.I’ll get back to you shortly with a detailed report.

U.S. Preparedness for Electromagnetic Pulse (EMP) Attacks

Introduction: Understanding the EMP Threat

An electromagnetic pulse (EMP) is a burst of electromagnetic radiation capable of disrupting or destroying electronic systems. EMPs can be generated by a nuclear detonation at high altitude or by non-nuclear devices, and similar effects can also arise from extreme solar geomagnetic stormswww.congress.gov. In 1962, the U.S. “Starfish Prime” test (a 1.4-megaton nuclear burst ~25 miles above the Pacific) famously demonstrated EMP effects: it knocked out streetlights and telephones in Hawaii 800 miles away and damaged satellites in orbitwww.congress.gov. Experts have since warned that a high-altitude nuclear EMP attack – for example, a single warhead detonated tens of kilometers above the U.S. – could shut down all electronics and power systems over a vast area, with cascading failures of interdependent infrastructure such as the electric grid, communications, water supply, transportation, and financewww.congress.gov. Even a naturally occurring solar super-storm (a Carrington-class event) or a non-nuclear EMP weapon could have catastrophic impacts on modern technology-dependent societywww.congress.govwww.congress.gov.U.S. officials consider an EMP attack a low-probability but high-consequence scenario. Congressional leaders have noted that the devastation from a widespread EMP “would actually probably pale in comparison” to more familiar disaster scenarios like a nuclear bomb in a city or a major cyberattack on the gridwww.congress.gov. For this reason, the U.S. government has investigated EMP threats for decades and increasingly prioritized planning for both man-made EMP (such as a high-altitude nuclear burst by an adversary or a non-nuclear radio-frequency weapon) and naturally occurring EMP from severe solar flares (geomagnetic disturbances). The following report provides a structured assessment of U.S. preparedness, drawing on congressional hearings, official reports, and military expert analyses. It examines the state of civilian and military infrastructure hardening, recent findings about EMP risks and consequences, and major steps taken over the past 20 years to mitigate this threat.

Types of EMP Threats and Potential Consequences

Nuclear High-Altitude EMP (HEMP): A nuclear weapon detonated in the upper atmosphere (roughly 30–400 km altitude) can produce a powerful EMP over a continental-scale area. Such a high-altitude EMP has three components: a fast, intense E1 pulse (nanosecond-scale burst frying electronics), an intermediate E2 pulse (akin to lightning), and a slow E3 pulse (seconds-long, inducing currents in long wires like power lines)sgp.fas.orgwww.congress.gov. A single nuclear burst could thus simultaneously damage unshielded computers, grid control systems, and high-voltage transformers over hundreds or thousands of miles. As one congressional report summarizes, if a nuclear weapon is detonated ~30 km or higher above the U.S., “the consequences of such an attack could be catastrophic. All electronics, power systems, and information systems could be shut down,” with cascading infrastructure failureswww.congress.gov. In the extreme case where power is not restored for many months, essential services (food, water, medical care) would collapse. A congressional commission expert testified that if the national power grid went down for a year, as much as 90% of the U.S. population could perish due to secondary effects (starvation, societal breakdown)www.congress.gov. This dire scenario underscores why a high-altitude nuclear EMP attack is often described as an “existential threat” to the United Stateswww.congress.govwww.congress.gov.Natural Solar Geomagnetic Storms: Solar flares and coronal mass ejections can induce geomagnetic disturbances (GMD) that are in some ways analogous to a long-duration E3 EMP effect. The most intense known solar storm, the 1859 Carrington Event, electrified telegraph lines and caused fires; if a similar event occurred today, it could induce extreme currents in the power grid, potentially burning out transformers and causing prolonged blackoutswww.congress.gov. Modern studies indicate that severe GMDs primarily threaten long-line electrical infrastructure (power grids, undersea cables) by inducing quasi-DC currents that overheat transformers and disrupt grid stability. Unlike a nuclear EMP, a solar EMP would not directly fry small electronics or cars – but a geomagnetic super-storm could take down regional or national power for days or weeks, indirectly disabling most critical services. Congressional hearings have explicitly noted that an EMP “caused by the sun, a solar event, or a man-made attack would be catastrophic” for the nationwww.congress.gov. The U.S. government therefore includes severe space weather in its EMP preparedness planning alongside man-made threats.Non-Nuclear EMP Weapons: In addition to nuclear and solar sources, there are also non-nuclear directed-energy weapons (e.g. high-power microwave devices) capable of localized EMP effectswww.congress.gov. These devices (sometimes called RF weapons or “e-bombs”) might be used by terrorists or adversaries to disable electronics in a confined area (for instance, wiping out computers in a building or disrupting avionics in an aircraft). While their range and intensity are far smaller than a nuclear HEMP, they still pose a threat to specific critical nodes. U.S. officials have warned that rogue nations or terrorist groups could develop rudimentary EMP capabilities without extremely sophisticated technologywww.congress.govwww.congress.gov. Indeed, military and intelligence assessments in the late 2000s noted that adversaries like Iran and North Korea were exploring EMP attack modes as an asymmetric tactic to offset U.S. conventional superioritywww.congress.govwww.congress.gov.Military Perspectives on EMP: From a national security standpoint, an EMP attack is attractive to adversaries because it could inflict widespread damage “with one or a few relatively unsophisticated nuclear-armed missiles,” potentially yielding greater strategic effect than destroying a single citywww.congress.gov. EMP strikes could cripple U.S. command and control and critical infrastructure with a single blow, and at a standoff distance that might evade traditional missile defenseswww.congress.gov. The 2008 congressional EMP Commission warned that both Russia and China had researched EMP weapons – and indeed a Pentagon official testified that “China’s military is working on exotic EMP weapons that can devastate electronic systems” similar to a nuclear blastwww.congress.gov. Cold War-era Soviet officials even threatened the use of EMP against the U.S. in past criseswww.congress.gov. Today, U.S. military experts consider EMP in war planning as a form of “blackout warfare.” A nuclear EMP attack by a rogue state or great power is still considered a remote scenario, but its potential consequences are so severe that it features in worst-case strategic assessmentswww.congress.gov.Summary of Consequences: In practical terms, a successful high-altitude EMP (or severe solar storm) over the United States could knock out large portions of the electric grid, communications networks, fuel supply chains, transportation systems, banking, and other vital services in an instant. Modern infrastructure systems are interlinked, so failures would propagate. As the 2017 DHS Strategy for EMP notes, the “effects of EMPs… can affect large geographic areas, disrupting elements critical to the Nation’s security and economic prosperity”, with even global impacts on stabilitywww.cisa.gov. While there is some debate among experts about the extent of damage (for example, whether a nuclear EMP would destroy most large power transformers or just a subset), there is consensus that unhardened infrastructure would face serious nationwide outagessgp.fas.orgsgp.fas.org. The Electric Power Research Institute (EPRI) and others have suggested the grid might suffer less-than-total failure if only a few key assets are damagedsgp.fas.org, but the U.S. EMP Commission firmly warned that, absent protective measures, a well-executed EMP attack could create an unprecedented catastrophe “holding our society at risk of catastrophic consequences”www.congress.gov. In either case, recovering from a nationwide power collapse – whether caused by a weapon or by the sun – would be an enormous challenge requiring weeks or months to restore critical functionssgp.fas.org. This looming risk has driven U.S. government efforts to harden infrastructure and improve response preparedness.

Congressional Hearings and Reports: Two Decades of EMP Warnings

Congressional EMP Commission (2001–2008): Alarm over EMP threats led Congress to charter the Commission to Assess the Threat to the United States from EMP Attack in the FY2001 defense authorization. The bipartisan EMP Commission’s mandate was to evaluate the threat and recommend protective steps for both military and civilian systemswww.congress.gov. The Commission’s landmark 2004 and 2008 reports alerted that U.S. critical infrastructures – especially the electric power grid – were highly vulnerable to EMP. The 2008 EMP Commission report specifically examined civilian infrastructure and concluded that an EMP attack could impose “catastrophic consequences” on the nation, potentially imperiling millions of liveswww.congress.govwww.congress.gov. The Commission noted that even relatively low-yield weapons could generate EMP fields strong enough to collapse the grid and that a “determined adversary can achieve an EMP attack capability without a high level of sophistication”www.congress.gov. Commissioners like Dr. William Graham (former Science Advisor to President Reagan) and Dr. Peter Vincent Pry repeatedly testified to Congress that modern society’s heavy dependence on electronics and just-in-time logistics makes it uniquely susceptible to an EMP-induced collapsewww.congress.govwww.congress.gov. This asymmetry – the U.S. being more technologically advanced and thus more vulnerable – was highlighted as a serious strategic concern.Key EMP Commission Findings: The EMP Commission’s analysis (drawing on testing and war-gaming) predicted that a large-scale EMP could knock out the electrical grid for an extended period, which in turn would paralyze other sectors reliant on power (communications, finance, fuel, water, etc.). Notably, the Commission warned that critical components with long replacement times, like extra-high-voltage transformers, could be permanently damaged by the EMP E3 pulse, meaning restoration of power could take months or longer if many of those transformers were destroyedsgp.fas.org. They also found that older analog equipment tended to be far more resistant to EMP than modern microelectronics – for instance, old electromechanical grid relays and 1960s-era vehicles might survive, whereas today’s digital controls and computerized vehicles could be friedsgp.fas.org. These findings implied that the U.S. had unwittingly built an increasingly fragile infrastructure. On the positive side, the Commission emphasized that solutions were available: “We know how to protect electrical and electronic devices from EMP. In fact, the Department of Defense has been doing it … for over 50 years.”www.congress.gov Hardening techniques (Faraday shielding, robust grounding, surge arrestors, etc.) were well-understood and had been proven in protecting military systems; the challenge was extending them to civilian infrastructure at scale.Commission Recommendations: In its final report and testimony to Congress, the EMP Commission offered a suite of recommendations to mitigate the threatwww.congress.govwww.congress.gov. These included: improving intelligence and missile defense to prevent an EMP attack; physically hardening key nodes of critical infrastructure (especially those “requiring long periods of time to replace” like big transformers)www.congress.gov; ensuring the U.S. military can sustain operations even if civilian grids fail (by identifying which infrastructure elements are vital to DoD and securing backups)www.congress.gov; developing plans for rapid emergency recovery of critical infrastructures after an EMPwww.congress.gov; and clarifying the roles of government vs. private sector in protecting the nation (since defending against foreign attack is inherently a federal responsibility, even though most infrastructure is privately owned)www.congress.gov. The Commission also urged that EMP preparedness be integrated with planning for other disasters (like cyber-attacks or severe hurricanes), because measures such as stockpiling transformers or installing backup generators would have “shared benefits” for resiliencewww.congress.gov. Congress was advised to provide oversight and require periodic progress reports on EMP readinesswww.congress.gov.Congressional Hearings: Throughout the 2000s and 2010s, numerous congressional committees held hearings to spotlight EMP threats and push for action. For example, a 2008 House Armed Services Committee hearing on “Threat Posed by EMP Attack” received the EMP Commission’s report; members noted it was that committee which had created the Commission in the first place and reauthorized it in 2006 to finish its workwww.congress.gov. At that hearing, Chairman Ike Skelton warned that EMP is “one of a small number of threats that can hold our society at risk of catastrophic consequences”, and witnesses detailed how adversaries like North Korea and Iran were testing missiles in ways “consistent with EMP attack” profileswww.congress.govwww.congress.gov. In a 2014 House Homeland Security Committee hearing, then-Representative Michael McCaul stated bluntly that while an EMP attack may be low-probability, the magnitude of damage “would be catastrophic” – likely worse than a ground nuclear detonation or major cyberattackwww.congress.gov. In the same hearing, Rep. Trent Franks (a leading advocate for EMP preparedness) entered into the record that protecting the grid is feasible: “Fortunately…we need not face such a horrific prospect. We know how to protect…EMP, and DoD has been doing it for the military’s nuclear deterrent and command-and-control systems for over 50 years.”www.congress.gov. Such hearings consistently stressed two themes: (1) public and private awareness of the EMP threat was insufficient, and (2) practical steps (legislation, standards, investments) were needed urgently to harden U.S. infrastructurewww.congress.gov.Legislative Actions: In response to these warnings, Congress slowly began legislating EMP preparedness. A breakthrough came with the inclusion of the Critical Infrastructure Protection Act (CIPA) in the FY2017 National Defense Authorization Act. Enacted in late 2016, this law amended the Homeland Security Act to specifically address EMP and geomagnetic disturbance protection across all 16 critical infrastructure sectorswww.ets-lindgren.com. CIPA directed the Department of Homeland Security (DHS) to incorporate EMP scenarios into national planning scenarios and to develop a comprehensive approach to improve EMP resilience in coordination with other agencieswww.congress.gov. It mandated research and development on EMP mitigation, designated roles for DHS to lead on protecting civilian infrastructure, and required periodic risk assessments (including a quadrennial EMP risk assessment)uscode.house.govuscode.house.gov. Essentially, after years of advocacy, Congress put the force of law behind the idea that DHS must plan and prepare for a catastrophic EMP event. (Table 1 below summarizes key government actions in the EMP preparedness effort since the early 2000s.)Table 1: Key U.S. Government Actions on EMP Preparedness (2001–2025)

Military vs. Civilian Infrastructure: Hardening and Vulnerabilities

Military Infrastructure and EMP Hardening: The U.S. military has long recognized the EMP threat in the context of nuclear warfare and has taken measures to harden critical systems. Key strategic assets – such as nuclear missile silos, command-and-control centers, ballistic missile early-warning radars, and communications networks used for nuclear command (NC3) – are designed to survive and operate through a nuclear EMP environment. For over five decades, the Department of Defense (DoD) has implemented EMP protection standards for its most critical hardwarewww.congress.gov. This includes shielding facilities with Faraday cages, using surge protectors and robust grounding, and employing electronics that can tolerate high voltages. As a result, the U.S. nuclear deterrent forces and associated command systems are expected to survive an EMP attack and continue functioningwww.congress.gov. For example, strategic military communications often use hardened infrastructure (e.g. ELF/VLF communications to submarines, satellite links with radiation-hardened components) and backup schemes to ensure messages can get through even if parts of the civilian grid are down.That said, not all military systems are fully EMP-hardened. Many routine military installations and equipment rely on commercial power and off-the-shelf electronics. The EMP Commission cautioned that the military’s dependence on civilian critical infrastructure is a serious weakness – bases need electricity and fuel, which ultimately come from civilian grids and pipelineswww.congress.gov. The Commission recommended DoD identify which civilian infrastructure nodes (for example, regional power substations serving key bases or telecommunication hubs used by military networks) are vital to its missions and either harden them or prepare to quickly “island” and supply those facilities independentlywww.congress.gov. The Pentagon has taken steps in this direction: many bases have backup diesel generators and some are developing on-site microgrids to reduce reliance on the public grid during an emergency. Still, until the surrounding civilian infrastructure is more resilient, military operations could be constrained by a wide-area EMP event. This concern persists in current assessments – indeed, in late 2024 the DoD’s Inspector General announced a review of EMP shielding for Pacific Command systems, indicating ongoing scrutiny of whether military infrastructure upgrades have kept pace with the threatwww.dodig.mil.U.S. military experts continue to evaluate worst-case scenarios. The Air Force’s Electromagnetic Defense Task Force (EDTF), in reports in 2019, highlighted that an EMP strike (or major solar storm) could severely challenge military readiness, and urged accelerating hardening efforts for systems like satellites, strategic airlift aircraft, and expeditionary forces that might have to operate with crippled infrastructure. Notably, satellites themselves can be vulnerable to high-altitude nuclear EMP – the pulse can travel through space and damage satellites line-of-sight to the detonation (as happened to several in Starfish Primewww.congress.gov). To mitigate this, some U.S. military satellites are built with radiation-hard electronics and self-protection circuits. The bottom line is that critical national security systems have a much higher degree of EMP resilience than civilian systems, thanks to decades of Cold War-era hardening, but gaps remain in the supporting infrastructure. The U.S. armed forces could “ride out” an EMP much better than the civilian population; however, sustaining prolonged operations would still be difficult if the nation’s economic and industrial base is devastated.Civilian Infrastructure Vulnerabilities: In contrast to military assets, most U.S. civilian infrastructure is minimally protected from EMP. The vast network of commercial power lines, substations, communications networks, transportation systems, and consumer electronics is designed for efficiency and low cost – not for withstanding nuclear-blast-level electromagnetic shocks. Congressional hearings have repeatedly noted that the U.S. electric grid – the linchpin of all other infrastructures – is the Achilles’ heel in an EMP scenariowww.congress.gov. A successful high-altitude EMP could induce massive voltages in long transmission lines, potentially overloading and damaging many high-voltage transformers simultaneously. These transformers are large, custom-built, and in limited supply; losing even a handful could cause regional blackouts lasting weeks or more. The EMP Commission warned that a continental-scale EMP could take down the grid for months, as transformer replacements and repairs struggle to keep upsgp.fas.org. Even more troubling, control systems and sensors that manage the grid (SCADA systems, protective relays) are now computerized and highly sensitive – an EMP’s E1 pulse could burn out these electronics over a wide area, making the grid uncontrollable in the immediate aftermathsgp.fas.orgsgp.fas.org. Modern smart grid technologies, while improving efficiency, also introduce millions of additional vulnerable points (smart meters, automated controls) that could be disabled unless shielded.Other civilian sectors would be hit hard mainly because of the power outage and electronics damage caused by EMP. Communications networks (internet backbone, telephone switches, cell towers) typically have backup power for a few hours (battery or generator), but if the grid is down long-term and fuel supply is disrupted, most communication could fail. Many telecom facilities are not EMP-hardened, meaning the electronics inside could be directly burned out unless they happen to be shielded by building structure. Broadcast stations, data centers, and satellites supporting civilian comms could also be knocked offline. Transportation relies on electricity and communications: pipelines need electric pumps, railways need signals, airports need radar and control towers. An EMP could thus bring transportation to a standstill. Financial systems heavily depend on data centers and networks – an EMP could wipe out servers or at least cut off their power, risking the loss of financial records (banks do have offsite backups, but restoring transactions would be chaotic under blackout conditions).Perhaps most immediately, water and food supply would be in jeopardy. Water treatment and distribution require pumps and control systems; most urban areas have only limited water storage. Grocery stores carry just a few days’ inventory and rely on computerized logistics. As former EMP Commission Chairman Dr. Graham starkly put it, in the event of a year-long nationwide blackout, tens of millions of Americans would likely perishwww.congress.gov – not from the EMP directly, but from the collapse of supply chains and critical life-support systems. This is why officials characterize EMP events (man-made or natural) as “catastrophic incident” scenarios that could dwarf other emergencieswww.congress.gov.Current Hardening Status: Despite the grim picture, there has been some progress in hardening or preparing civilian infrastructure in recent years. The electric power industry, prompted by regulatory and legislative pressure, has started to address the threat of solar geomagnetic storms. The North American Electric Reliability Corporation (NERC) now has mandatory GMD standards: utilities must model the impact of a benchmark solar storm, install geomagnetic monitoring, and in some cases add hardware (like series capacitors or neutral ground resistors) to reduce GMD-induced currents. These measures, while focused on natural GMD, also impart some resilience that would be useful in an EMP (particularly against the E3 component). However, no broad regulations yet require hardening against the fast E1 pulse of a nuclear EMP, which is largely considered a national security threat beyond the normal purview of civilian regulators. The industry’s stance has been that more research is needed to quantify the risk. Organizations like EPRI have been conducting EMP vulnerability tests on grid equipment (for example, test-bed experiments on transformers and relays) to see how they fail and how to protect themsgp.fas.orgsgp.fas.org. These studies have shown that many grid components can be fortified with relatively inexpensive steps – e.g. improved shielding of control cables, better surge protection, using fiber-optic links instead of long copper lines – which “significantly reduce, but not eliminate” vulnerability to EMPsgp.fas.org. Some utilities have voluntarily begun to install such protections at critical substations (especially those near military bases or critical government facilities). Industry efforts like Spare Transformer programs (stockpiling spares for emergencies) and mobile transformer deployment units also help improve recovery capability.DHS and DOE have been working with industry on pilot projects. For instance, the Department of Energy’s CESER (Cybersecurity, Energy Security, and Emergency Response) office has EMP/GMD programs to develop hardware devices that can block EMP-induced currents and to perform modeling of grid responsesgp.fas.org. There have been small-scale demonstrations where an EMP simulator is used on a section of grid to test protective measures. All of this is progress, but it’s far from comprehensive. A 2016 GAO review found that only 3 out of 11 major electric utilities surveyed had even studied their EMP vulnerabilities, indicating a lack of widespread action at that timesgp.fas.org. While awareness has grown since then, most civilian infrastructure remains essentially as-built – meaning highly exposed to EMP. As Chris Krebs (former CISA Director) acknowledged in 2020, “over the past year, we have worked with interagency and industry partners to identify the footprint and effects of EMP threats… and [are] developing approaches to improving the Nation’s resilience,” but it is a long-term project and the work is just beginningwww.dhs.govwww.dhs.gov.To illustrate the current state of hardening, the table below summarizes several infrastructure sectors and what is known about their EMP resilience:Table 2: U.S. Infrastructure Categories – EMP Hardening and Expected Resilience

Recent Assessments and Ongoing Initiatives

In the last few years, U.S. military and homeland security experts have continued to refine their understanding of EMP risks. The consensus is that the threat is real and potentially devastating, even if the probability of a high-end EMP attack is uncertain. U.S. Strategic Command and other defense planners factor in the possibility that adversaries could use an EMP strike at the outset of a conflict to disable U.S. communications and power. For instance, intelligence analyses indicate that Russia and China have incorporated EMP attack scenarios into their military doctrine, and both have tested weapons for this purposewww.congress.govwww.congress.gov. North Korea’s two satellites currently in orbit raised concern a few years ago, since an EMP device detonated from orbit could, in theory, have effects similar to a high-altitude burst. While there is no public confirmation that those satellites carry nukes, the mere possibility kept EMP on the agenda during North Korea crises. In 2017, at the height of North Korean missile testing, the regime’s state media explicitly threatened an EMP attack, describing it as a “strategic weapon” that could wipe out the United States power grid. This rhetoric further pushed U.S. officials to act.From the homeland security side, DHS in 2018–2020 made a concerted push to institutionalize EMP preparedness. The 2018 DHS EMP and GMD Strategy set goals for risk assessment, protection, and deployment of mitigation technologieswww.dhs.gov. Following the 2019 Executive Order, DHS’s Cybersecurity and Infrastructure Security Agency (CISA) stood up an EMP program management effort. By September 2020, DHS reported it had identified priority infrastructure at greatest risk, begun testing vulnerability of key equipment, and was formulating guidance for industry on cost-effective hardeningwww.dhs.govwww.dhs.gov. One notable achievement was developing an interagency understanding of National Critical Functions that need protection – essentially mapping out which functions (like “maintain power generation” or “provide 911 emergency communications”) must be preserved or restored quickly after an EMPwww.cisa.govwww.cisa.gov. This helps target hardening efforts to the most important assets.The Department of Energy has been researching technologies such as EMP-resistant grid components. For example, there is ongoing development of EMP blocking devices that can be installed at transformer neutrals to prevent damaging currents, and advanced surge arrestors to clamp E1 pulses. The Department of Defense, under the EO 13865, also conducted its own assessments of how an EMP might affect DoD-critical infrastructure and worked to share some of its military hardening expertise with civilian partners. In 2021, DoD (in coordination with DHS and DOE) reportedly completed a “quadrennial EMP risk assessment” as required by lawuscode.house.gov, briefing Congress on the areas of highest risk. Although details are mostly classified, this effort likely informed further investments. Congress has continued to ask for updates – for instance, the National Defense Authorization Act for FY2022 required the Secretary of Energy to report on the ability to reconstitute the grid after an EMP and to evaluate the feasibility of protecting large transformers.Crucially, debates over the severity of EMP effects continue to some degree, which affects how resources are allocated. On one side, the EMP Commission and many in Congress argue that the worst-case must be planned for – meaning essentially preparing for a nationwide blackout scenario. On the other side, some industry groups and scientists suggest that while EMP is a threat, certain extreme predictions (like multi-year blackout or 90% mortality) may be over-estimating the damage; they point to studies (EPRI, Oak Ridge National Lab) that indicate a nuclear EMP might not uniformly destroy all critical componentssgp.fas.org. Those studies found, for example, that many large transformers might survive the E3 pulse with only limited damage, and that the grid could possibly be restarted quicker in some areas if control communications can be kept operablesgp.fas.org. However, even these more optimistic analyses concede that if control systems are lost and even a modest number of transformers fail, there could be cascading outages that take a long time to fixsgp.fas.org. Given the uncertainties, U.S. policy has leaned toward caution: hardening key nodes (which also helps against other threats like cyber or physical sabotage) is seen as insurance against a very high-impact event.

Ongoing and Future Initiatives

• Grid Resilience Upgrades: Through the Infrastructure Investment and Jobs Act (2021) and other legislation, funding has been authorized for grid modernization and resilience. Some of these funds are being applied to projects that inherently boost EMP resilience – e.g. upgrading old transformers (new ones can be built with better surge suppression), deploying distributed energy resources (microgrids with local storage can isolate and keep critical facilities powered during a larger grid failure), and installing sensor networks to give early warning of geomagnetic storms. The Department of Energy’s EMP resilience program is expected to demonstrate advanced protection technologies in the coming years and develop best-practice guides for utilities.
• Improved Forecasting and Warning: For solar EMP threats, the U.S. has improved space weather forecasting. NASA, NOAA, and the U.S. Space Force operate satellites and ground sensors that monitor the sun and can provide 30–60 minute warnings of an incoming solar storm (enough for grid operators to take defensive actions, like adjusting voltages or isolating parts of the grid). In October 2020, the PROSWIFT Act was enacted to enhance coordination on space weather R&D. While this doesn’t prevent an EMP, it can mitigate impact by giving operators a chance to prepare (unfortunately, for a nuclear EMP launched by surprise, there would be little to no warning time for the public grid).
• Federal Response Planning: FEMA and North American Aerospace Defense Command (NORAD) have periodically conducted exercises simulating EMP events. For example, “Dark Sky” and “Black Start” exercises have tested procedures for recovering from a nationwide power outage. The armed forces have practiced operating in communications-denied environments, effectively simulating EMP-like effects. These drills have driven home the complexities of such a scenario: they often reveal shortfalls in backup systems and the need for better stockpiles of generators, fuel, and spare electronics. The federal government is updating continuity of government plans to ensure leadership can communicate even if commercial networks fail. There is also renewed focus on civil defense-style preparedness: educating the public on having emergency supplies, backup power (like solar chargers or generators), and old-fashioned tools (like battery radios) that could be invaluable if modern gadgets go dark.
• International Cooperation: The U.S. isn’t alone in facing this threat – allies in Europe and Asia also worry about EMP (both solar and nuclear). There are ongoing dialogues in NATO about protecting military systems and assisting civilian infrastructure. For example, after experiencing a damaging grid blackout from a solar storm in 1989, Canada has worked closely with the U.S. on GMD response strategies. International standards bodies (IEC) are developing standards for EMP-resistant equipment, which U.S. industry can adopt as they become available.

Conclusion: Are We Prepared?

Over 20 years of study and incremental action, the United States has improved its awareness and planning for EMP attacks, but significant vulnerabilities remain. On the positive side, the U.S. military’s critical deterrent and command systems are well-protected, and government continuity plans are in place to ensure leadership can survive and communicate through an EMP crisiswww.congress.gov. There is also better interagency coordination today than a decade ago – DHS, DoD, DOE, and other key departments have established frameworks for tackling EMP risks, and Congress has given clear mandates to keep the issue on the agendauscode.house.govuscode.house.gov. Some physical improvements to infrastructure are underway, especially to address the solar storm aspect of the threat (e.g. hardening the grid against geomagnetic currents). These efforts mean that not all lights would be permanently “out” even in a severe EMP scenario: critical government and military functions would continue, and with concerted emergency response, pockets of infrastructure could be restored to provide life-sustaining services in the aftermath.That said, as of 2025 the consensus of expert assessments – including the latest congressional and military reports – is that U.S. civilian infrastructure is still largely not hardened against a high-altitude EMP attacksgp.fas.orgsgp.fas.org. The national electric grid and other utilities would be extremely vulnerable should a determined adversary employ an EMP weapon. DHS acknowledges that “reducing the risk is a long-term effort” and much work remains to achieve sustainable, cost-effective resilience measureswww.cisa.govwww.cisa.gov. In practical terms, this means that if an EMP strike (or severe solar super-storm) happened tomorrow, the United States would likely suffer a multi-region power outage and the majority of civilian electronic systems in the affected area would fail. Parts of the infrastructure that could survive or be quickly restored – for example, hardened emergency communications networks, isolated microgrids powering hospitals or bases, and pre-stocked backup systems – would provide some islands of functionality. Essential services would eventually be re-established, but the timeline could range from days for initial emergency power in some areas to weeks or months for full national recoverysgp.fas.org.In summary, U.S. preparedness for EMP attacks has advanced from theoretical studies to concrete action plans and initial hardening steps. Congress and the military have treated the issue with bipartisan urgency, as reflected in hearings and laws over the past two decades. The latest Pentagon and DHS assessments underscore that EMP is a complex threat requiring a whole-of-nation approach: from thwarting would-be attackers, to engineering resilience in our grids and networks, to planning how to feed and care for Americans in a protracted blackout. While the nation’s infrastructure today is not fully hardened, momentum is building to ensure that in the coming years it will be far less fragile. The United States’ challenge is to implement the known solutions faster than adversaries can exploit the weaknesses. As one Congressman said, “there is a moment in the life of nearly every problem when it is big enough to be seen and still small enough to be addressed. We now live in that moment as it relates to EMP”www.congress.gov. In 2025, that window is still open – and U.S. policy is firmly focused on fortifying the country against the unique and formidable danger of an EMP attack.Sources: This report is based on information from U.S. congressional hearing records, official commission and agency reports, Department of Defense assessments, and federal agency statements on EMP preparedness. Key sources include the Congressional EMP Commission’s 2004 & 2008 reports, transcripts from House and Senate hearings on EMP (2008, 2014, etc.), the DHS Strategy (2018) and Program Status Report (2020) on EMP/GMDwww.dhs.govwww.dhs.gov, the 2019 Executive Order on EMPwww.dhs.gov, the Congressional Research Service Report R47339 (2022) on electric infrastructure resiliencesgp.fas.orgsgp.fas.org, and analyses by the GAO and Department of Defense. These primary sources collectively highlight both the progress made and the ongoing urgency in protecting America’s critical infrastructure from EMP threats.