The purpose of the exercise was to prepare for the mass migration of people from Caribbean islands due to powerful and devastating hurricanes. It brought together the Department of Homeland Security, US Southern Command, and other federal agencies. The 600 participants who gathered at Fort Sam Houston in Texas for a week-long simulation faced a primary challenge: to prevent migrants from reaching the United States by intercepting them and repatriating them at sea.

“Our goal was to move people, equipment and supplies as quickly as possible to the affected areas, as well as provide the Navy and Coast Guard with additional surveillance assets to locate migrants at sea,” said Lt. Gen. Chris Nowland, the 12th Air Forces Southern commander, in a statement from 12th Air Force public affairs.

This scenario of hunting down and interdicting migrants in the ocean may sound like the stuff of Trumpian nightmares, but the simulation was carried out in 2015 under the administration of President Barack Obama, whom pundits celebrated for his identification of climate change as a “national security” threat. The exercise, which took place as record numbers of refugees were drowning in the Mediterranean, was not unique to Obama: It was carried out before and after his administration, in a number of forms, part of broad efforts of the US security state to prepare for, as the 2022 National Security Strategy put it, “the existential challenge of our time.”

Treating climate change as a “national security threat” may seem like wise environmental policy, and indeed many liberal environmental and climate groups have welcomed this nice-sounding embrace by the national security state. The military and deportation apparatuses are, after all, consistently well-funded and resourced US bodies, and them “taking climate seriously” gives a sense of progress: If the hard-nosed military is doing something about this, then maybe the rest of the society will be right behind.. But the reality has played out differently. The vast bulk of resources are not spent on mitigation, much less reducing carbon extraction and emissions, but on defending the United States and its allies against unrest, mass migration, and potential resource conflicts.

The Pentagon and Department of Homeland Security do not exist to foster global cooperation to mitigate and adapt to the shared crises. They are bodies most adept at killing, disappearing, and surveilling. And they have become the country’s main vehicles for responding to social crises and destabilization. Under both Democratic and Republican administrations, the US government has underinvested in civilian responses to climate change and instead focused its resources on shoring up fortress America.

While the Trump administration is scrubbing official mentions of climate change, its belligerent military actions abroad and ICE occupations at home are, in fact, climate policies: They’re showcasing how the US state is orienting itself in regards to displacement, hardship, and the very idea of global cooperation toward a shared end. US society is getting a look into the logical conclusion of using might to respond to suffering and social upheaval.

The stories of children detained at a concentration camp in Dilley, Texas; of a lawn mower left idling because the man driving it has been abducted and disappeared; of ICE observers shot dead in the street—are stories of climate crisis.

If you take all of the climate spending of the US government, it amounts to roughly $40 billion a year, according to Lindsay Koshgarian, program director for the National Priorities Project. This number comes from the climate investments in the Inflation Reduction Act, the biggest source of climate spending, and is very much a ballpark estimate. “Climate spending is so complex and scattered throughout the budget,” Koshgarian explained. “This doesn’t include Trump’s significant cuts to climate spending, but it also doesn’t include a variety of relatively small programs that exist across multiple agencies and aren’t always clearly identified.”

The $40 billion figure includes money for questionable programs like carbon capture and alternative fuels, and it also includes tax incentives for private industry. This is not, in other words, a budget that exclusively reflects efforts to keep fossil fuels in the ground, which is what scientists say we need to do if we want to stave off the worst scenarios of climate change. But the $40 billion number can give us a sense of where our priorities lie.

For comparison, Congress approved a military budget of more than $1 trillion for the federal year of 2026. This includes $167.5 billion to buy major weapons systems and $145.9 billion to research, develop, and test weapons platforms, bringing the total spent on weapons purchase and research to $313 billion, according to Koshgarian. That means that weapons companies—the same corporations whose bombs are dropping on Iran—got nearly eight times as much public funding as climate programs.

More than half of the annual federal discretionary budget goes toward militarized arms of the state, which also includes the vast deportation apparatus. If Congress passes additional funding at 2025 levels, the combined budget of Customs and Border Protection and Immigration and Customs Enforcement for the federal year of 2026 will be $64.9 billion. That’s 162 percent of the amount spent on the climate spending.

“The Trump administration has really intensified those long-standing trends around gutting of state capacity for anything other than war and violence, gutting civilian and regulatory functions of the state,” said Lorah Steichen, policy manager for global systems and policy at the Climate and Community Institute, a progressive climate and economic research think tank.

Spending disparities predate the current era. From 2013 to 2018, CBP and ICE had combined budgets of $19.6 billion per year, Todd Miller, Nick Buxton, and Mark Akkerman note in a 2021 report for the Transnational Institute. In contrast, the United States spent an annual average of $1.1 billion on climate finance, which refers to grants and concessional funding sent to Global South countries to help them mitigate and adapt to climate change, and assist people who need to move across borders in order to survive its devastating impacts.

Some have criticized the framework of climate finance, and instead called for climate reparations, but finance spending nonetheless provides a glimpse into social priorities. This imbalance is not unique to the United States. The report finds that seven major greenhouse gas emitters—the United States, Germany, Japan, the United Kingdom, Canada, France, and Australia—“collectively spent at least twice as much on border and immigration enforcement (more than $33.1 billion) as on climate finance ($14.4 billion) between 2013 and 2018.” The report states, “These countries have built a ‘Climate Wall’ to keep out the consequences of climate change.”

Such disparities are not just a matter of misallocating resources. Prioritizing investments in militarized institutions over investments in civilian climate mitigation and adaptation means that the United States is choosing to answer to suffering, displacement, and social destabilization with force. In his 2012 book Tropic of Chaos: Climate Change and the New Geography of Violence, Christian Parenti called this “the politics of the armed lifeboat: responding to climate change by arming, excluding, forgetting, repressing, policing, and killing.”

A growing body of research shows climate change worsens conflict and causes mass displacement. The UN Refugee Agency said climate-related disasters triggered “more than half of new reported displacements in 2022” and reported in 2025 that “over the past 10 years, weather-related disasters have caused some 250 million internal displacements.” Upheaval is expected to increase dramatically if meaningful action is not taken to curb climate change. The Institute for Economics and Peace, a think tank, said there could be 1.2 billion people displaced by climate change–related disasters by 2050. The World Bank estimates the climate crisis will internally displace up to 216 million people by 2050.

While armies don’t often talk openly about how they plan to respond to crises, there are indicators. The US military has identified climate change as a concern going back to the Clinton administration, and has studied the issue for far longer. During the administration of George W. Bush, the Pentagon commissioned a report looking at a number of possible “abrupt” climate change disasters that could arise. Under extreme scenarios, the report states, “Humanity would revert to its norm of constant battles for diminishing resources, which the battles themselves would further reduce even beyond the climatic effects. Once again warfare would define human life.”

The Obama administration cited climate change as “an urgent and growing threat to our national security” in its February 2015 National Security Strategy. An October 2014 blog post from Secretary of Defense Chuck Hagel refers to climate change as a “threat multiplier” and says, “We are considering the impacts of climate change in our war games and defense planning scenarios, and are working with our Combatant Commands to address impacts in their areas of responsibility.”

But what exactly are these “areas of responsibility”? The US military specializes in violence—not in protecting people around the world from a common crisis, or addressing the root causes of climate change. This was demonstrated by Marine Gen. John F. Kelly, then head of the US Southern Command, when he asked Congress in 2015 for $28 million “to upgrade a pop-up tent city at the US Navy base at Guantánamo that could be used in case of a Caribbean migrant surge,” as summarized by Carol Rosenberg for the Miami Herald. He said the money would be used for “basic horizontal infrastructure” that would be needed “in the event of a maritime mass migration.” Michael T. Klare wrote in his 2020 book, All Hell Breaking Loose, “While it is possible to imagine a number of scenarios that might trigger mass migration, coastal flooding and resulting economic damage from ‘climate change-related sea level rise’ have to be prominent among them.”

It is grimly absurd to discuss a threat to humanity in terms of how it will affect US bases, installations, and fighting power, but that is how the military has talked about the climate crisis. One Department of Defense climate risk assessment from 2018 says, “Our warfighters require bases from which to deploy, on which to train, or to live when they are not deployed. If extreme weather makes our critical facilities unusable or necessitate costly or manpower-intensive work-arounds, that is an unacceptable impact.”

In October 2021, the Biden administration released a series of reports showing that climate change is a national security threat. A consistent theme was the focus on how climate change could affect “warfighting infrastructure.” One Department of Defense report flags the dangers that extreme weather and rising sea levels pose to “warfighting infrastructure” in the Indo-Pacific. “For example, the United States has important defense assets located in Guam, the Marshall Islands, and Palau, all of which are vulnerable to these hazards. Additionally, competitors such as China may try to take advantage of climate change impacts to gain influence.”

The implication that entire societies sinking into the ocean is a problem because it could weaken the US position and strengthen China shows why the US military is structurally incapable of responding to climate change with solidarity and compassion.

In All Hell Breaking Loose, Klare noted that soon after Donald Trump became president in 2017, he rescinded an Obama-era executive order that instructed federal agencies to take actions to “enhance climate preparedness and resilience.” Top military leadership may have changed the way it talked about climate change, but it did not stop recognizing the danger. Klare, The Nation’s defense correspondent, wrote, “While discussion of climate change has indeed largely disappeared from the Pentagon’s public statements, its internal efforts to address the effects of global warming have not stopped. Instead, a close look at Pentagon reports and initiatives reveals that many senior officers are convinced that climate change is real, is accelerating, and has direct and deleterious implications for American national security.”

In his second term, Trump is even more aggressively attacking any action to mitigate the climate crisis—and even the idea of climate change itself. On February 11, Trump issued an executive order instructing the military to source more of its power from coal-burning plants. And the November 2025 National Security Strategy says, “We reject the disastrous ‘climate change’ and ‘Net Zero’ ideologies that have so greatly harmed Europe, threaten the United States, and subsidize our adversaries.”

Yet that same National Security Strategy references national disasters, which are increasing in intensity, frequency, and deadliness under human-made climate change: “We want a resilient national infrastructure that can withstand natural disasters, resist and thwart foreign threats, and prevent or mitigate any events that might harm the American people or disrupt the American economy.”

Even if the Trump administration rejects mention of climate change, it is offering a bleak vision of a national fortress in the face of large-scale human suffering. The November 2025 National Security Strategy states as the first priority, “The era of mass migration must end. Border security is the primary element of national security. We must protect our country from invasion, not just from unchecked migration but from cross-border threats such as terrorism, drugs, espionage, and human trafficking.”

This is a climate policy, whatever the president calls it.

It might seem reasonable to try to attach climate measures to the national “security” state, which receives tremendous funding and backing by both Republicans and Democrats. The US military is by far the most heavily funded in the world (greater than the next nine militaries combined), and the deportation apparatus, if it were an army, would be the 13th largest.

“Environmental groups and other interest groups assume that they can hitch their priorities to the national security apparatus to get federal resources and elevate the status of a problem,” said Steichen from the Climate and Community Institute. “There’s various dangers to this approach. One of them is looking at the ways that problems are solved through the national security apparatus by militarized responses. If you’re framing climate change as a national security issue, the most robustly funded and resourced arms of the national security state are militarized, so the types of responses one can expect are quite predictable.”