President Donald Trump has reportedly suggested on multiple occasions that the United States withdraw from NATO — a maneuver that would roil the global community and signal a major victory for Russia.

Julian Barnes and Helene Cooper at the New York Times reported on Tuesday that in 2018, Trump said several times that he wanted to remove the US from the North Atlantic Treaty Organization, a military alliance between the US, Canada, and multiple European countries signed in 1949 to contain Soviet expansionism after World War II.

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Trump has made no secret of his disdain for NATO, which he once declared was “obsolete.” According to the Times, his repeated requests to withdraw from NATO have rattled administration officials, especially as concerns about his interactions with Russia and President Vladimir Putin grow.

The report details officials’ efforts to keep Trump contained during the NATO summit in Brussels last July, including pushing ambassadors to finish an agreement on several goals before the meeting to “shield it” from Trump. He discussed internal business in front of nonmembers of NATO, bucking protocol, and complained — as he often does publicly — that NATO members aren’t spending enough on defense.

He reportedly especially took issue with German Chancellor Angela Merkel and her country’s spending of 1 percent of its GDP, per the Times:

By comparison, the United States’ military spending is about 4 percent of GDP, and Mr. Trump has railed against allies for not meeting the NATO spending goal of 2 percent of economic output. At the summit meeting, he surprised the leaders by demanding 4 percent — a move that would essentially put the goal out of reach for many alliance members. He also threatened that the United States would “go its own way” in 2019 if military spending from other NATO countries did not rise. During the middle of a speech by Ms. Merkel, Mr. Trump again broke protocol by getting up and leaving, sending ripples of shock across the room, according to American and European officials who were there. But before he left, the president walked behind Ms. Merkel and interrupted her speech to call her a great leader. Startled and relieved that Mr. Trump had not continued his berating of the leaders, the people in the room clapped.

A meeting to celebrate NATO’s 70th anniversary planned for April in Washington, DC, has also been downgraded to a foreign ministers’ gathering, and it will no longer take place in Washington.

Trump’s antipathy toward NATO is a good thing for Russia, whether he ultimately withdraws from the agreement (which would require a one-year notification period and likely see pushback from Congress) or not. Moscow benefits from divides between the US and Europe, and Putin has been trying to undermine ties between the two for years.

With the exit of Defense Secretary Jim Mattis in December, the situation has become worse, not better. In his resignation letter, Mattis wrote that he believes the United States’ strength is “inextricably linked” to the strength of the country’s “unique and comprehensive system of alliances.” He specifically invoked NATO and pointed out that the 29 countries in the alliance at that time came to America’s defense after the 9/11 terrorist attacks.

As Vox’s Alex Ward wrote on the heels of the 2018 summit, Trump doesn’t seem to understand NATO or its worth:

At the heart of the NATO military alliance is a provision known as Article 5. That says that an attack on one NATO country is to be considered an attack on all the countries — and therefore that all the member countries are obligated to come to the defense of whoever is attacked. This is why NATO allies — yes, including Montenegro — are fighting alongside the US in Afghanistan to this day. The US invoked Article 5 after 9/11, and NATO countries kept their promise and came to America’s aid.

The Times report confirms he still doesn’t get it.