Twenty-five years after 9/11 made terrorism the organising idea of Western security, the world it produced is coming apart in unexpected ways. The charts below explore how the post-9/11 security order has evolved, with Trump pushing Europe to carry more of the military burden, American voters growing wearier of foreign wars, and terrorism itself losing its centrality in Western foreign policy.
Trump has put NATO on notice—Europe, not US is raising its spending
The post-9/11 security order was built around an America willing to spend, deploy and fight far from home, while Europe remained comparatively sheltered under the US military umbrella. Twenty-five years later, that bargain is being forcefully rewritten. US military spending rose from about $858 billion in 2014 to $929 billion in 2025, an increase of roughly 8%. Meanwhile, Europe’s climbed even faster, more than doubling from $372 billion to $792 billion.
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The acceleration came after Russia’s full-scale invasion of Ukraine in 2022. Trump, who had been criticising NATO’s unequal burden-sharing since his first presidential campaign in 2016 has since turned that complaint into more of a threat. During the 2024 campaign, he said he would “encourage [Russia] to do whatever the hell they want” to members that failed to spend enough on defence. Last year, NATO agreed to a new 5%-of-GDP defence and security spending target by 2035. (See Chart 1)
America First has run into an American war
The politics that followed 9/11 gave Washington a long leash abroad. In 2002, 77% of Republicans told the Chicago Council that America should take an active role in world affairs. By 2023 that had fallen to 47%, before rebounding to 59% in 2025. That recovery did not mark a return to the neoconservative appetite for remaking countries. The 2025 survey came weeks after Trump ordered strikes on Iranian nuclear facilities, an action backed by a majority of Republicans, suggesting that much of the MAGA base remained comfortable with short, punitive uses of force even while rejecting open-ended wars.
{{/usCountry}}The politics that followed 9/11 gave Washington a long leash abroad. In 2002, 77% of Republicans told the Chicago Council that America should take an active role in world affairs. By 2023 that had fallen to 47%, before rebounding to 59% in 2025. That recovery did not mark a return to the neoconservative appetite for remaking countries. The 2025 survey came weeks after Trump ordered strikes on Iranian nuclear facilities, an action backed by a majority of Republicans, suggesting that much of the MAGA base remained comfortable with short, punitive uses of force even while rejecting open-ended wars.
{{/usCountry}}Also Read: 25 years after 9/11: The warnings, ‘muscle hijackers’ and details you may not know
Iran has since exposed how difficult that distinction is to maintain. Trump has avoided the ground war that would collide with the politics he built, while relying on air and naval power to force Tehran to bend. Six months on, the conflict is stuck in a costly stalemate and Republican support has begun to erode—a Reuters/IPSOS poll had found that only 36% Americans support the war with Iran while Trump’s approval rating is stuck at the lowest in his political career at 33%. The lesson of Iraq was that America could start a war much more easily than it could dictate how one ended. Iran is beginning to revive that problem. (See Chart 2)
The war on terror is fading. But the war isn’t
And that is an important distinction to make because “war on terror” was always larger than terrorism itself.
The Uppsala Conflict Data Program (UCDP) defines a state-based armed conflict as fighting over government or territory in which at least one of the main parties is a state and the violence causes at least 25 battle-related deaths in a year. That makes it a useful lens for the post-9/11 era, which quickly spilled beyond terrorist attacks into wars involving governments, insurgencies and foreign armies.
Also Read: The wrong turn that US strategy took after 9/11
In 2001, interstate conflicts accounted for only 1,445 of 23,623 battle deaths recorded by UCDP, barely 6%. By 2025 they accounted for 97,440 of 153,643, almost two-thirds. Meanwhile, deaths attributed to terrorism itself has moved in the opposite direction. The Global Terrorism Index, which measures deaths from attacks classified as terrorism, puts the 2025 toll at 5,582, roughly half its 2015 peak of 10,882.
To be sure, the old enemy has not vanished. The Taliban is back in Kabul and Islamic State remains the world’s deadliest terrorist network as of 2025. But jihadism is no longer at the forefront of Western foreign policy. As Philip H Gordon, international relations scholar and former national security advisor to the US Vice President, puts it in a recent essay written for the Foreign Affairs Magazine, reviewing journalist Peter Bergen’s new book “All the Presidents’ Wars”, “when Americans mark the 25th anniversary of the 9/11 attacks this fall, the threat of Islamist terrorism will certainly not be gone. But the war on terror, the guiding framework for U.S. foreign policy for the previous quarter century, will be.”
The irony is that jihadism has lost its old grip on Western foreign policy just as arguments over Islam, migration and national identity have moved deeper into domestic politics on both sides of the Atlantic. (See Chart 3)