As the U.S. and Ukraine advance a proposed 30-day ceasefire, European leaders find themselves in a complex and uncertain position. With Washington recalibrating its strategic priorities, concerns over the future of transatlantic security are mounting. Joav Toker, professor at the American Graduate School in Paris, points to a growing divide among European leaders: Some believe the U.S. is no longer a dependable ally and that Europe must take greater control of its own defense; others argue that decades of deep-rooted cooperation make the transatlantic alliance indispensable, despite shifting global dynamics.