MADRID \u2013 NATO may be \u201cthe most successful alliance in history\u201d \u2013 as its secretary-general, Jens Stoltenberg,\u00a0claims<\/a>\u00a0\u2013 but it may also be on the brink of failure. After a turbulent few years, during which US President Donald Trump has increasingly turned America\u2019s back on NATO, tensions between France and Turkey have escalated sharply, laying bare just how fragile the Alliance has become.<\/p>\n The\u00a0Franco-Turkish spat<\/a>\u00a0began in mid-June, when a French navy frigate under NATO command in the Mediterranean attempted to inspect a cargo vessel suspected of violating a United Nations arms embargo on Libya. France\u00a0alleges<\/a>\u00a0that three Turkish ships accompanying the cargo vessel were \u201cextremely aggressive\u201d toward its frigate, flashing their radar lights three times \u2013 a signal indicating imminent engagement. Turkey denied France\u2019s account, claiming that the French frigate was harassing its ships.<\/p>\n Whatever the details, the fact is that two NATO allies came very close to exchanging fire in the context of a NATO mission. That is a new low for the Alliance \u2013 one that may herald its demise.<\/p>\n Lord Hastings Ismay, NATO\u2019s first secretary-general, famously quipped that the Alliance\u2019s mission was to \u201ckeep the Russians out, the Americans in, and the Germans down.\u201d The dynamic obviously changed over the subsequent decades, especially the relationship with Germany. But the broad basis of cooperation \u2013 a common perceived threat, strong American leadership, and a shared sense of purpose \u2013 remained the same.<\/p>\n Without US leadership, the whole structure is at risk of crumbling. It is no coincidence that the last time two NATO allies came this close to blows \u2013 during the Turkish invasion of Cyprus in 1974 \u2013 the US was preoccupied with the Vietnam War. In fact, the spat between Turkey and France occurred just days after it was\u00a0revealed<\/a>\u00a0that Trump had decided, without any prior consultation with America\u2019s NATO allies, to withdraw thousands of US troops from Germany.<\/p>\n Germany may no longer be on the front line, as it was during the Cold War, but US forces there still serve as a powerful deterrent to Russian aggression along NATO\u2019s eastern flank. By drawing down those forces, Trump has sent a fundamental message: ensuring European security is no longer a top US priority.<\/p>\n While America\u2019s drift away from Europe has accelerated under Trump, it began over a decade earlier. In 2011, when Trump\u2019s predecessor, Barack Obama, was touting his \u201cpivot to Asia,\u201d then-US Secretary of Defense Robert Gates\u00a0warned<\/a>\u00a0that, unless NATO proved itself relevant, the US may lose interest. NATO did no such thing: until last December, its summit declarations failed even to\u00a0acknowledge<\/a>\u00a0the challenges posed by China\u2019s rise. By then, the US had lost interest. And now, under Trump, that disinterest has become open hostility.<\/p>\n Without the US as a rudder, NATO allies have begun to head off in different directions. Turkey is the clearest example. Before the recent squabble with France, Turkey\u00a0purchased<\/a>\u00a0a Russian S-400 missile-defense system, despite US objections. Moreover, it has brazenly intervened in Libya, providing air support, weapons, and fighters to the Tripoli-based Government of National Accord.<\/p>\n Turkish President Recep Tayyip Erdo\u011fan seems confident that his\u00a0direct relationship<\/a>\u00a0with Trump will protect him from suffering any consequences for his behavior. Trump\u2019s decision not to impose sanctions over the missile purchase, beyond cutting Turkey\u2019s participation in the F-35 fighter jet program, seems to vindicate Erdo\u011fan\u2019s reasoning.<\/p>\n But Turkey is not alone in striking out on its own; France has done the same, including in Libya. By providing military support to the Russian-backed General Khalifa Haftar, who controls eastern Libya, to fight Islamist militants, France has gone against its NATO allies. While President\u00a0Emmanuel Macron<\/a>denies<\/a>\u00a0supporting Haftar\u2019s side in the civil war, he did recently express support for Egypt\u2019s pledge to intervene militarily against Turkey, which he says has a \u201ccriminal responsibility\u201d in the country.<\/p>\n As tensions with Turkey rise, France is more insistent than ever that a European approach to security and defense \u2013 one that would be\u00a0de facto\u00a0<\/em>led by France \u2013 is vital. The fact that popular support for Macron within France is\u00a0waning<\/a>\u00a0only augments his sense of urgency.<\/p>\n