Published: April 28, 2026
Amid U.S. involvement in a war against Iran, President Donald J. Trump has decided to double down on previous public expressions of disregard and distrust toward NATO. President Trump has threatened to withdraw the United States from NATO several times since his reelection. His repeated jibes at the alliance have raised concern among European defense experts and government officials. Former U.S. Ambassador to NATO Ivo Daalder recently noted that “It’s hard to see how any European country will now be able and willing to trust the United States to come to its defense.” And French President Macron indicated on April 2nd that, in his view, U.S. President Trump was undermining NATO through his repeated threats to withdraw from the alliance. Raising new fears of American abandonment on the part of European leaders, Trump, in various interviews and social media posts within a few days, said that the United States “will remember” France’s refusal to assist in the war against Iran; that NATO was a “paper tiger”; and that “Putin knows that, too, by the way.”
The most recent Presidential broadsides against NATO reflected Trump’s frustration with European allies who chose not to involve themselves in the war against Iran and/or denied their political and military support for the actions taken under Operation EPIC FURY—an effort that Secretary of War, Hegseth describes as “laser-focused [to] destroy Iranian offensive missiles, destroy Iranian missile production, destroy their navy and other security infrastructure – and they will never have nuclear weapons.” But this hesitancy among European allies should not have surprised U.S. leadership. Neither NATO as an alliance nor individual European governments were consulted before the decision to go to war, nor were they fully informed until the operation was already in progress. Further to the issue of NATO support, Trump’s address to the nation on April 1st simply assumed that the United States would wind up its military operations within several weeks and would turn the problem of unblocking shipping in the Strait of Hormuz over to European countries and others. In addition, Western European governments have strong public support for putting distance between themselves and the war in Iran. Popular majorities in every country oppose the U.S. and Israeli campaign, and European opposition to the war is enhanced by Trump’s personal unpopularity on that side of the Atlantic.
An additional element in the split between Trump and NATO was the Russian interpretation of its implications for the war in Ukraine, and more broadly, for Russia’s national security strategy writ large. Prolonged U.S. commitment to war in the Middle East could deplete the availability of military assets that would otherwise be available to sustain Ukrainian forces in their fight against Russia. The global spike in gas and oil prices was an obvious boon to the Russian economy and, from the standpoint of Ukrainian President Volodymyr Zelensky, an unwelcome distraction for European leaders from the priority of supporting Ukraine. Russia also took advantage of Epic Fury to reinforce its support for Iran by providing targeting information for Iranian missile attacks against Israel and other regional states. Russia and Iran had already been sharing technology and knowledge with respect to drone warfare even prior to the launch of military operations against Tehran.
To some extent, the volatility in the Trump administration’s approach to NATO reflected the President’s frustration at his inability to broker a peace agreement between Ukraine and Russia. Vladimir Putin viewed Russia’s war as existential and refused to acknowledge that there was any distinction between Ukrainian and Russian civilizations, let alone sovereignties. The Ukrainians responded in kind, resisting Russia’s invasion and occupation of Ukrainian territory with creative use of drone technology and edgy defensive strategizing that put at risk a variety of targets in Russian territory, including bomber bases and critical infrastructure. Worse for Putin, his invasion in 2022, preceded by Russia’s annexation of Crimea in 2014, refocused NATO on its primary mission of deterrence and defense in Europe as opposed to “out of the area” operations such as Iraq and Afghanistan. Even the formerly Cold War neutral states, Sweden and Finland, were added to NATO’s membership because of Russia’s attempted coup de main against Kiev that turned into the longest and most destructive war in Europe since World War II. Caught in a trap of his own making, Putin continued to pour troops and material into the battlefields of Donbas and elsewhere in eastern Ukraine to support a more favorable negotiating position, should productive negotiations ever materialize.
Given Trump’s propensity for rearranging the deck chairs on foreign policy via Truth Social memoranda, it is conceivable that he will tone down the anti–NATO rhetoric once he has decided on a strategy for winding down the U.S. military campaign in Iran. The process of deconflicting the Strait of Hormuz will likely involve participation from European nations and other countries. Almost nobody benefits from continued bottlenecks in global shipping of oil and other vital commodities. Regardless of the outcome in Iran, the United States needs NATO, and NATO needs the United States. Without the U.S. as the indispensable leading partner, NATO Europe has insufficient nuclear or conventional deterrence against further Russian aggression. This assertion implies no disregard for the steps that the U.S. European allies have already taken since 2022 to improve the quality of their armed forces and military–industrial complexes. It is instead a recognition that the unique American nuclear deterrent and conventional war-fighting capabilities, supported by European determination to resist further Russian aggression, create a global as well as a regional deterrent for Russia and its partners (The CRINKs – China, Russia, Iran, and North Korea) that benefits not only NATO but also world peace. On the other hand, a divided and internally fractious NATO invites further aggression within and beyond Europe.
Stephen J. Cimbala is Distinguished Professor of Political Science at Penn State Brandywine and the author of numerous works on nuclear deterrence, arms control, and military strategy. He is a senior fellow at NIDS and a recent contributor to the Routledge Handbook of Soviet and Russian Military Studies edited by Dr. Alexander Hill (Routledge: 2025). The views of the author are his own.
About the Author
Stephen Cimbala
Dr. Stephen Cimbala is Distinguished Professor of Political Science at Penn State university, Brandywine. He is currently a senior fellow with the National Institute for Deterrence Studies.
