Along the campaign trail, Donald Trump said a number of things that concerned prominent Democrats and foreign leaders. Some of these things can be chalked up to campaign rhetoric, but few of these remarks made the heads of foreign governments wiggle uncomfortably in their chairs more than his stance on NATO.

In what would become a controversial series of statements made to the New York Times during his campaign, President-elect Trump explained that, under his administration, the military might of the United States may not be forthcoming to the other members of the NATO alliance in their times of need. Trump went on to explain that, while the United States has always been one of the primary financiers of the organization, not all member nations are contributing as they should be.

Among foreign leaders and American Democrats, these statements were seen as sacrilege. The North Atlantic Treaty Organization dates back to 1949, when its founding members chose to combine their political and military strengths to present a unified front against Soviet (read: communist) expansion, prevent the revival of nationalist militarism the likes of which the world encountered in both world wars, and encourage the political integration of European and North American nations. In effect, the organization was intended to prevent a third world war, in large part by rebuking what was then seen as the most likely candidate to start it: the Soviet Union.

So why on Earth would Donald Trump take such a controversial stance on such an important and historically significant organization? In the face of a new era of Russian posturing, Chinese naval expansion, North Korean nuclear weapons, and wars in multiple theaters, what could possibly lead America’s president-on-standby to consider weakening alliances with other nations? The world seems primed for conflict and sparks in Syria, the South China Sea, and Iraq could all feasibly light the fuse. Why, now more than ever, would we choose to stop honoring the agreements we’ve made with friendly nations?