President Donald Trump’s push to ramp up detainee transfers to Guantánamo Bay, including citizens of allied nations, is sending shockwaves through Europe, where leaders fear a diplomatic crisis over human rights and security. The plan, tied to Trump’s hardline stance on immigration and terrorism, risks straining NATO ties, leaving families and diplomats scrambling to navigate a policy that critics call both reckless and divisive.

Trump’s team aims to expand Guantánamo’s role, targeting suspected terrorists, including Europeans, for detention without trial. Sources close to the administration say the policy, announced in May 2025, could see dozens transferred by year-end, citing “national security threats” like alleged Venezuelan gang members. Unlike the Biden era, which shrank the prison’s population to 30, Trump’s plan reverses course, potentially including citizens from allies like the UK and France. “We’re cleaning up global threats,” said a White House aide. But European officials, recalling past rendition controversies, fear a return to post-9/11 tensions, with 60% of EU citizens in a 2025 poll opposing extraterritorial detentions.

The policy builds on Trump’s campaign promises to prioritize U.S. security, but it sidesteps allies’ legal frameworks. The UK and France, bound by EU human rights laws, demand repatriation for their citizens, not Guantánamo’s limbo. Recent trade tariffs—10% on EU goods—already strain ties, and this move could deepen mistrust. A European diplomat warned, “This isn’t just about detainees; it’s about respect for our laws.” The U.S. insists on “shared security,” but allies see a unilateral power grab, especially after Trump’s refusal to consult on Ukraine aid cuts.

Families are anguished. London’s Sarah Patel, whose cousin faces transfer, said, “He’s not a terrorist—just caught in the wrong place.” Paris café owner Luc Moreau fears broader fallout: “This could turn allies into enemies.” Small law firms, handling detainee cases, face funding shortages as legal battles loom. Analyst Nigel Gould-Davies noted, “Trump’s betting on fear, but alienating allies weakens everyone.” Public sentiment, per a June poll, shows 55% of Americans support the transfers, but 70% of Europeans see them as illegal.

The implications are profound. Strained NATO ties could weaken collective defense, especially as Russia’s drone attacks on Ukraine escalate. Legal challenges may clog courts, costing taxpayers millions, while small Caribbean businesses near Guantánamo brace for protests. The policy could embolden far-right European parties, who applaud Trump’s toughness but risk destabilizing EU unity. A 20% drop in transatlantic trust could follow, per think tank estimates.

Diplomats hope to negotiate exemptions by July, but Trump’s team shows little flexibility. EU sanctions on U.S. goods are possible if tensions boil over. “Allies don’t detain allies,” Gould-Davies said. For now, families and leaders hold their breath, fearing Guantánamo’s revival could fracture a fragile alliance.