The U.S. plans on filling Eastern Europe with thousands of troops along with vehicles and weapons to equip an armored combat brigade. That will require a special budget request of $3.4 billion for next year.

An unnamed administration official told the New York Times, that the step “fulfills promises we’ve made to NATO” and “also shows our commitment and resolve.” Moreover, said another anonymous aide: “This reflects a new situation, where Russia has become a more difficult actor.”

However, the basic question remains unanswered: Why is the U.S. defending Europe? The need for America to play an overwhelming role disappeared as the continent recovered and the Cold War ended.

Today NATO involves collective defense, but “their,” not “our,” defense. Although the Europeans sometimes join America in “out of area” activities, for which no alliance is necessary, they have never come to, and are unlikely to ever come to, America’s actual defense. Applying Article 5 after 9/11 was a nice act of solidarity, but European support was never necessary to strike al-Qaeda and oust the Taliban.

Nor is there any serious military threat to Europe. Russia may be “a more difficult actor,” but it is not a suicidal aggressor. Russia has gone from Soviet Union back to Russian Empire.

Vladimir Putin’s Russia cares about border security. It wants to be respected and have its interests protected. It doesn’t act precipitously, but it does act.

Moscow responded to what it perceived as Western provocations in Ukraine. That didn’t justify Russia’s support for Ukrainian separatists, but it was far different than a Hitleresque Blitzkrieg across Ukraine. Indeed, Putin wanted to weaken rather than swallow his neighbor, which would be indigestible.

Moreover, if this really is a “new situation” and “changed security environment,” why don’t the Europeans act like they believe that? The countries theoretically most at risk, the Europeans, continue to cut their military outlays and capabilities. As always, NATO stands for “North America and the Others.”

According to the alliance’s latest annual report, total NATO Europe expenditures went from $275 billion in 2010 to $253 billion last year. As percentage of GDP outlays have slipped from 1.64 to 1.43.

A majority of European countries have cut their spending. Overall, U.S. expenditures ran a bit more than 2.6 times those of Europe in 2010. The disparity had increased to almost 2.8 times in 2015.

Although NATO aspires to devote two percent of its members’ GDP to the military, NATO Europe managed just 1.43 percent overall. Only Estonia, Greece, Poland, and the United Kingdom hit the two percent level. Several of the alliance’s most important members fell below even this mediocre average.

On defense expenditures per capita the numbers are particularly striking. Last year the U.S. devoted $1865 per person to the military. NATO Europe spent $446 per person. Several European countries barely broke the $100 level.

The Eastern Europeans are theoretically at the greatest risk but do not impress with their efforts. They put little effort into their defense.

But NATO Secretary General Jens Stoltenberg proudly announced that the Europeans cut military outlays only a little last year. That’s his good news.

U.S. expenditures are down as well, but mainly because the U.S. no longer is so intensely fighting so many wars. The Obama administration is merely reducing the massive Bush build-up. And as a percentage of GDP America’s outlays are more than double those of the Europeans. Even though the U.S. faces even fewer serious military threats than does Europe.

World War II ended long ago. If the Europeans feel endangered, they should take action.

 After all, as I wrote for Forbes: “the U.S. is very busy in the world. Moreover, the U.S. government is effectively bankrupt. Washington no longer can afford to garrison the globe.”

The world is changing. So should America’s national security priorities. Europe should take over its own defense.