Earlier this week, at a press conference marking the end of the war in Afghanistan, Joe Biden delivered what is arguably the most encouraging remark of his presidency to date: “This decision about Afghanistan,” said Biden, “is not just about Afghanistan. It’s about ending an era of major military operations to remake other countries.” Given Biden’s own history, of course, there are good reasons to be skeptical about the sincerity of these words — and, fittingly enough, plenty of the standard imperial liturgy could be found amid his defense of the withdrawal.

Nevertheless, even as the administration officially pitches a shift away from the logic that has guided America’s foreign policy since 9/11, the toxic residue of the “war on terror” is almost certain to linger. Representing a new, destructive, and bloody paradigm in the history of US power, the last two decades have seen a growing culture of militarization that is arguably unprecedented.

As presidents, Democratic and Republican alike, projected America’s terrifying military might abroad with catastrophic human cost, the posture of open-ended war against a series of often ethereal and vaguely specified threats undeniably changed the tenor of life at home as well. From the growth of a sprawling domestic security apparatus to an increasingly brutal immigration policy, the martial ethos of the war on terror gradually embedded itself throughout the major institutions of American life and brought with it a domestic price tag that ultimately deflected trillions in public spending away from other priorities.

Though we’ll inevitably be parsing this noxious legacy for decades to come, a new report offers some hard numbers about the extent to which the policies of the last twenty years have further militarized American society — and come with a price tag almost beyond comprehension. State of Insecurity: The Cost of Militarization Since 9/11, newly published by the Institute for Policy Studies, details the breathtaking financial and human consequences of the war on terror. Using data drawn mainly from the Office of Management and Budget (OMB), authors Lindsay Koshgarian, Ashik Siddique, and Lorah Steichen set out to calculate the overall cost of militarization since 2001. Their key finding — that the United States has spent a stunning $21 trillion on foreign and domestic militarization over the past two decades — alone makes the report worthy of attention.

In many ways, however, their journey to this conclusion is every bit as revealing. Noting correctly that the war on terror’s financial cost hasn’t been limited to spending on tanks, drones, and cruise missiles, the authors include a whole swathe of expenditures in their calculations: from those at the Department of Defense (DoD) and Central Intelligence Agency (CIA) to international military assistance, veterans’ benefits, and military-related expenses incurred by other federal agencies (the war on terror, it turns out, also conscripted the National Science Foundation and Maritime Administration).

Domestic security spending is also included, meaning the $21 trillion figure ultimately incorporates funds allocated to the Department of Homeland Security (DHS) and Immigrations and Customs Enforcement (ICE). Their rationale is straightforward and convincing: “We include most programs in the Department of Homeland Security (DHS),” the authors write, “because of the agency’s origins in the post-9/11 response, and because of its core mission to safeguard the country and borders from external threats.”

All told, they calculate that some $16 trillion has gone into military spending (at least $7.2 trillion being on military contracts), with $3 trillion going to veterans’ programs, $949 billion to DHS, and another $732 billion going to federal law enforcement. As a result, the Pentagon budget is now higher than it was at the zenith of the Cold War or during operations in Vietnam, Korea, and the Persian Gulf, ultimately making up more than half of the federal discretionary budget in a typical year. Though such spending peaked in 2010 and has fallen modestly since, it remains far above pre-2001 levels — and is sure to be inflated in the coming years by ongoing operations in Somalia and belligerence toward China (among other things).

In other words: the era of the war on terror may officially be over, but its impact on both American and global society will continue to be felt for years, and possibly decades, to come. Having caused nearly a million deaths worldwide according to one estimate, twenty years of American militarism has also displaced thirty-seven million people around the world.

As the authors rightly argue, the embrace of different priorities could have yielded an altogether different reality than the one we inhabit today. For a mere fraction of the cost of what the war on terror extracted from the Treasury, America could have fully decarbonized its electrical grid, erased student debt, extended the COVID-era’s anti-poverty Child Tax Credit for ten years, guaranteed free preschool, funded COVID vaccines throughout the world — and still have had money to spare.

It’s an astonishing insight into the kind of society America might be if its elites abandoned their commitment to militarism and war.