Berger Warns Trump’s Iran Policy and Troop Cuts Are Fracturing U.S. Alliances
In a May 4, 2026 interview on Background Briefing with Ian Masters, Thomas Berger, Professor of International Relations at the Pardee School, warned that the Trump administration’s approach to Iran and Europe is severely straining U.S. alliances and undermining long‑standing security arrangements.
Berger argued that President Trump’s decision to withdraw roughly 5,000 U.S. troops from Germany was driven less by strategy than by political grievance, after German Chancellor Friedrich Merz publicly criticized Washington for lacking a clear Iran policy. Berger described the episode as “probably a poor choice of words, especially given Trump’s sensitivities on the question of humiliation and appearances of strength,” adding that it triggered “our president’s fit of pique” and punitive troop cuts that weaken deterrence in Europe.
Berger emphasized that U.S. allies are now paying the economic price for a war they neither endorsed nor helped shape. “Trump launched this attack with no consultation whatsoever with any of our allies, except Israel,” he said, noting that European and Asian economies, particularly energy importers, face “grave” consequences from instability in the Middle East. Compounding the damage, Berger pointed out, is what he sees as a troubling contradiction in U.S. policy: “Trump then blames them for not doing more, not helping him out more in clearing the Straits of Hormuz.” In Berger’s assessment, “it’s not the brightest moment in U.S. alliance politics.”
For Germany, the security implications are especially serious. Berger stressed that removing a U.S. brigade from the Munich area “weakens the U.S. tripwire, the U.S. deterrent, extended deterrent, which we provide to Germany,” a non‑nuclear state that depends heavily on American security guarantees. That erosion comes amid mounting European intelligence concerns about future Russian hybrid warfare and alongside new economic pressure from U.S. tariffs on European cars.
Taken together, Berger portrays a pattern of no consultation, economic harm, public blame, and punitive measures that signals a deeper breakdown in U.S. alliance management; one that is leaving allies angry and increasingly uncertain about Washington’s reliability.
The full interview can be listened to here.
Thomas Berger is a professor of international relations at the Pardee School of Global Studies at Boston University. He is the author of War, Guilt and World Politics After World War II, Cultures of Antimilitarism: National Security in Germany and Japan and is co-editor of Japan in International Politics: The Foreign Policies of an Adaptive State. His articles and essays have appeared in numerous edited volumes and journals, including International Security, Review of International Studies, German Politics, and World Affairs Quarterly. To learn more about Professor Berger’s academic contributions, visit his faculty profile.