Holding the Line: A Transatlantic Conversation on Defense and Security

On Monday, June 22, 2026, the Sciences Po American Foundation hosted the 2026 Sciences Po DC Transatlantic Forum, focused on defense, security, and the future of the transatlantic relationship. Sponsored by Airbus and held at the French Residence ahead of a cocktail reception, the evening gathered the Sciences Po community, alumni, and Washington foreign-policy figures for a candid discussion on an alliance under strain.

The discussion featured General David H. Petraeus (former Director of the CIA, former commander of coalition forces in Iraq and Afghanistan, current Partner and Chairman of the KKR Global Institute) and Professor Thierry Balzacq (Professor of International Relations at Sciences Po, Professorial Fellow at its Centre for International Studies). The conversation was moderated by Robert Geckle (former Chairman and CEO of Airbus U.S. Space & Defense, newly named CEO of Thales USA and North America, and Sciences Po exchange alumnus).

Geckle opened by noting that the transatlantic relationship has endured past crises, from the Suez crisis to the “Freedom Fries” era, and tends to recover over time. He framed the discussion around three simultaneous pressures: Europe’s rearmament, renewed transatlantic tensions, and intensifying U.S.–China competition.

Asked whether Washington’s current NATO posture is a lasting shift or a tactic, Petraeus said it is “probably a bit of both.” He noted that burden-sharing disputes are longstanding and welcomed Europe’s increased defense spending, driven by pressure from President Trump and the threat from Vladimir Putin- who, he quipped, is “the greatest gift to NATO since the end of the Cold War.” He expected some reversion under future administrations while the U.S. modestly shifts focus toward the Pacific, stressing that America remains the alliance’s keystone.

Balzacq placed France’s push for strategic autonomy in historical context, tracing it to de Gaulle’s post-war vision of grandeur and independence. He argued this instinct was later “Europeanized” and now underpins broader ideas of European sovereignty. For France, autonomy is closely tied to identity - “living by your own laws” - and requires first defining what Europe wants to be before focusing on capabilities.

Pressed on what credible European deterrence without American support would actually require, Petraeus replied that the honest answer would “start by spending $1 trillion extra on defense a year” - and that even then, Europe’s ambitions have always outrun its resources. The United States still spends more than twice as much on defense as all its NATO allies combined; France’s roughly $70 billion budget this year sits beside an American budget approaching $950 billion. But money, he argued, is not the deepest problem. The alliance has not yet grasped the need for “institutional change”: a wholesale rethinking of how its militaries are organized, trained, and equipped.

Here Petraeus delivered the evening’s most arresting material, describing how Ukraine is “redefining warfare.” Ukrainian forces, he said, now deploy more than ten thousand drones a day and have created a 35-kilometer “death zone” along the front, in which manned vehicles cannot survive; trenches have given way to underground survivability positions resupplied by unmanned ground vehicles. The next leap (autonomous systems that no longer require a human pilot) is already arriving, alongside the millions of drones Ukraine will manufacture this year. Adapting will mean new force structures (Ukraine has stood up a dedicated Unmanned Systems Force that now inflicts the majority of Russian casualties), new ways of buying weapons, and defense industries able to update their software weekly. 

“This is a break-glass moment,” Petraeus said, urging allies - including his own country - to abandon business as usual. He cautioned, though, against drawing the wrong lessons: militaries should study Ukraine firsthand, but adapt what they learn to their own geography.

On China, Balzacq argued Europe cannot remain a spectator to the U.S. China rivalry- even if it wished to be- given the EU’s exposure to industrial competition and emerging technologies like AI. He predicted the transatlantic relationship will be “tested very strongly,” as Europe weighs between a middle position and deeper alignment with the U.S. framework.

The audience pressed both speakers further. Asked how allies should deal with an unpredictable Washington, Petraeus drew on a lesson from his years as CIA director: deal with the world “the way it is, not the way you’d like it to be.” Some leaders, he observed, have managed the relationship pragmatically and to their advantage; others have made statements in the heat of emotion that served their countries poorly. A second question on whether the laws of war can be built into autonomous weapons drew a detailed answer: such systems, he said, must carry algorithms grounded in the law of armed conflict and the Geneva Convention, much as rules of engagement were in Iraq and Afghanistan, and a human should remain “in the loop” wherever communications allow. The harder frontier, he noted, is “autonomous systems of autonomous systems” and the coming era of “agentic warfare” - a prospect that lent his call for urgency added weight.

Geckle closed on a deliberately hopeful note. Reflecting on the 250th anniversary of American independence and France’s standing as America’s oldest ally, he likened the partnership to an extended family: “We’re family. We have no choice. We need each other.” Disagreements, he suggested, are part of the bond rather than a threat to it.

Written by Adam Radwan (Sciences Po ‘26)