Save the date: Donald Trump made perhaps the most frightening statement of his presidential campaign on June 20, in an interview with The New York Times.

Sure, he said he would "pull out of Nafta in a split second," and gave Turkey's increasingly authoritarian president praise for "being able to turn [the recent coup] around." But his comments on the 67-year-old North Atlantic Treaty Organization are what made heads spin around the globe.

When asked if America's NATO allies — like Germany, Italy and France — could count on our support in the event of an attack, Trump responded, "Have they fulfilled their obligations to us? If they fulfill their obligations to us, the answer is yes."

The whole point of NATO, as Zack Beauchamp explained for Vox, is that the allies' unwavering commitment to each other makes other countries think twice about attacking.

"[The treaty] works by credible commitment," Beauchamp explained. "If the United States signals that it is fundamentally committed to the NATO treaty, then it sends a signal to Russia and other hostile powers that the US will abide by the term of its agreements. This deters them from launching wars or any other kind of military adventurism in an American-aligned state."
Trump's statement is the opposite of that promise.

The United States created NATO after WWII, in order to deter Soviet expansion in Europe. The alliance still provides comfort to smaller European nations — especially those on the Russian border. To make things more awkward, the promise of protection has been utilized only once: In the NATO allies' promise to defend the U.S. after September 11. 

The condemnation against Trump's NATO comments — from U.S. politicians as well as allies — was swift. 

White House spokesman Josh Earnest confirmed the country's "ironclad" commitment to NATO. Former NATO Supreme Allied commander James Stavridis said Trump's proposal would "deeply damage the underpinnings of the global system and work to America's profound disadvantage." Even Senate majority leader Mitch McConnell, who spoke on Trump's behalf at the Republican National Convention, said he disagreed with the candidate's views. 

But Toomas Hendrik Ilves, the president of Estonia, had perhaps the most poignant response. "We are equally committed to all our NATO allies, regardless of who they may be," he tweeted."That's what makes them allies."