Opinion | NATO Has to Change. Here’s How.

What would Ike say now?

Gen. Dwight Eisenhower, NATO’s first supreme allied commander Europe, felt strongly that his mission was to get Europeans “back on their military feet” — not for American troops to become the permanent bodyguard for Brussels and Berlin.

“If in 10 years, all American troops stationed in Europe for national defense purposes have not been returned to the United States,” he wrote of NATO in 1951, “then this whole project will have failed.”

But as leaders of NATO allies gather in Washington on Tuesday for the alliance’s 75th anniversary, some 90,000 U.S. troops are stationed in Germany, Italy, Britain and elsewhere, making up a significant portion of the 500,000 NATO troops on high readiness.

America’s outsize presence comes not just in the form of troops. Of the $206 billion in military and nonmilitary aid allocated to Ukraine by countries around the world, $79 billion has come from the United States, according to the Ukraine Support Tracker database. Since about 1960, the United States’ share of allied G.D.P. has averaged roughly 36 percent, while its share of allied military spending has been more than 61 percent, according to a Cato Institute report. The supreme allied commander Europe has never been a European.

It is now becoming increasingly clear that Europeans need to shoulder more responsibility for their own defense. That’s not just because Donald Trump and an isolationist wing of the Republican Party complain bitterly about having to defend wealthy countries that, by the way, can afford social safety nets that America can only dream of because they don’t spend as much on their militaries. It’s also because U.S. officials are becoming more focused on the challenges posed by China, which will require an increasing amount of attention and resources in the years ahead, especially given the growing cooperation among China, Russia, North Korea and Iran.

The United States simply can’t do everything everywhere all at once, by itself. The future requires well-armed, capable allies. The indispensable nation has to be a bit less indispensable.