Theres been plenty of drama in President Donald Trump s first month, from the resignation of his national security advisor to the road-blocking of his refugee executive order. But in at least one area of policy, he has reason to celebrate. Trump promised during his campaign to make sure Americas NATO partners stepped up their defense spending to meet their obligations, and already the Europeans are responding positively.

Last week, during a brief and frank speech at NATO headquarters, Secretary of Defense James Mattis unleashed his inner Mad Dog and demanded that his European counterparts start shouldering their portions of the alliances burden. No longer can the American taxpayer carry a disproportionate share of the defense of Western values, he said. Americans cannot care more for your childrens future security than you do.

A few European leaders, among them European Commission President Jean-Claude Juncker, bristled at Mattis ultimatum . But generally the response was receptive. The president of Finland saw it as a duh moment : Our position is what has been agreed should be fulfilled, he said, thats so simple in my opinion. Many European nations, spurred by Trumps election, were already beefing up their defense anyway. In late November, the European Union announced a plan for its member governments to spend an additional $5.8 billion on their militaries. The Baltic nations, menaced by Vladimir Putin, vowed to triple their military spending by 2018, as Lithuanian officials conceded to the Associated Press that Trump was right about NATOs lopsided funding.

And lopsided it is. According to NATOs own figures, the United States covers a full 72 percent of the alliances total defense spending.

The combined wealth of the non-U.S. Allies, measured in GDP, exceeds that of the United States, the alliance says . However, non-U.S. Allies together spend less than half of what the United States spends on defense. NATOs charter requirement that members spend at least 2 percent of their GDPs on their militaries is met by only five nations the United States, the United Kingdom, Poland, Estonia, and Greece.

That last one is an especially glaring embarrassment. If recession-throttled Greece can muster up the 2 percent, why cant France? And why does Canada spend a piddling 0.99 percent of its GDP? Those who fawn over European-style welfare states omit an important subtext: Those welfare states are only affordable because their governments drain their defense budgets, courtesy of the United States taxpayer-funded security guarantee.

With Americas national debt edging toward $20 trillion and Europe daunted by new challenges from Russia to refugees, Washington cant afford to bankroll the socialist indulgences of wealthy allies anymore. The Europeans have sheltered themselves under our protective awning for long enough. As our adversaries catch up to our capabilities thanks in part to 15 years of us being overextended on failed regime change campaigns, America needs strong allies willing to stand at her shoulders.

That means one nation in particular. All eyes now fall on Germany, that reluctant pillar of European power. Berlins spending on defense is scarcely above 1 percent of GDP and somewhat understandably. Since the electroshock of World War II, German governance has been animated by two principles: balanced budgets and military restraint. Both are needed considerations if youre, say, the United States, profligate with defense appropriations and hung over from fruitless nation building in the Middle East. But right now, Germany has the opposite problem. Continental Europe increasingly looks to Berlin for leadership, even as the German military stagnates, known more for its generous pensions than its fighting strength .

Digging out of this hole will be a daunting task for the Germans, fiscally and philosophically, but it is a necessary one. Other nations like Italy and Poland should contribute, too, but their economies simply arent large enough for them to make a serious dent in NATOs defense deficit.

Germany has responded admirably to its past and more than atoned for its sins. In todays world, radically different from the one strewn by war in 1945, we need the Germans to be the ballast of Europe, and that means having a formidable military, one that can work in conjunction with Americas to fight the enemies who threaten us all.

So give the president some credit when it comes to NATO. Thanks to Trump, that alliance seems just a little less cobwebbed than it did before.