One year into Donald Trump’s presidency, it’s clear this White House isn’t one for carefully picking its battles. And given the president’s appetite for confrontation, it is only matter of time before the U.S. and its allies end up in a pointless fight over EU defense.

A Pentagon official this week criticized the EU’s “common security and defense policy” (CSDP) for pulling forces away from NATO, and the U.S. ambassador to the alliance warned against its provisions to protect European defense companies. This will make for awkward conversations at the Munich Security Conference this week, where the allies intend to push back against talk of a NATO divided under Donald Trump.

The U.S. is right to suspect that Europe’s decision to build up a robust defense policy is not all good news for NATO. But it’s making its point the wrong way. Attacking Europe’s push for greater security cooperation won’t make it reverse course, and could do damage to an already frayed transatlantic relationship.

We’ve been here before: George W. Bush’s first government spent four years trying to block EU defense, before concluding that it’s better to channel the initiative than to stop it.

To be sure, if you’re American (or Canadian or Norwegian) there’s a whole lot not to like about CSDP. It did nothing to boost European defense budgets, it made even more of a mess of the already tricky task of joint weapons development, and, yes, it will make life more difficult for non-European defense companies.

The original sin of many of the policy’s supporters was to claim that EU governments would be more likely to spend money on defense if it’s organized under the EU flag, rather than NATO. But defense budgets in Europe continued to fall even after CSDP was rolled out, and it took a war (Russia’s against Ukraine) to reverse the trend.

Critics also argue the policy pits the EU against NATO, making them competitors for member countries’ attention and money. That remains a worrying possibility. The EU’s new defense pact, known as Permanent Structured Cooperation (PESCO), for example, commits participating states to using the EU’s defense agency if they want to develop new weapons jointly. But the agency prioritizes weapons needed for EU missions, not NATO ones.

The U.S. and other non-EU weapons-producing countries (chiefly Norway and soon the U.K.) also believe, rightly, that CSDP is gaming the rules of defense procurement in favor of companies based on EU soil.

Most European companies reply that it’s only fair. The U.S. government, after all, protects its own suppliers too. The truth is more complicated. The U.S. may have scored more visible successes selling to the Europeans than the other way around, but both markets are somewhat open, while openly favoring national champions, to protect jobs and the security of supply in times of war. And Washington is right to point out that many Europeans prefer to buy American because they get a security relationship with the U.S. above what NATO offers. Those ties could be severed if European defense integration proceeds.

But despite these potential pitfalls, the U.S. would be foolish to keep attacking Europe’s defense integration.

Europe is trying a novel approach to an issue that has plagued NATO and Europe in equal parts: the wasteful process whereby European countries buy their weapons.

The vast majority of all orders goes to national champions, often in order to protect jobs. Because home markets are small, the economies of scale are awful and the final price tags unnecessarily high. The EU is now offering to pay as much as 20 percent of the total price from common budgets if the governments in question pool their orders. This is a promising idea that, if it takes off, will benefit both the EU and NATO. There are other similarly useful lines of work under way in Europe, which would make it easier to move military equipment across EU borders, or harmonize the standards of equipment used by its militaries.

Skeptics say the benefits don’t measure up to the costs of CSDP, and claim Washington would be right to seek to thwart defense integration in Europe. But an outright opposition is doomed to fail.

More EU countries support greater cooperation now than was the case in the early 2000s, when the U.S. tried to stop CSDP from taking root. It’s not that the Europeans are blind to its shortcomings, but that they see the potential for benefits that the U.S. does not share or care about: protecting European defense industries, a chance to advance the broader case for EU integration, or a price worth paying for remaining at the innermost core of EU countries.

The policy is already a reality, whether the U.S. likes it or not. Enough European members of NATO are willing to stand up for it to make it pointless for Washington to try to thwart it.

The U.S. should do what previous administrations have done for the past decade: Work with like-minded allies to encourage the promising aspects and work the usual diplomatic channels to press back against the worrying parts. This is a policy best conducted offline — and off Twitter.

This article was originally published by Politico Europe.