Can Europe confront Russia without US help? Not yet, but it may have to.

Germany, Europe’s economic giant, has just embarked on a revamp of its defense policy that until a few weeks ago would have been nothing short of unthinkable.

The same could be said of the latest transatlantic contretemps: hostile sneers directed at America’s European allies by two top U.S. officials, in what they believed was a private chat, planning Washington’s recent airstrikes in Yemen.

And the two are related.

They are both signs of a fraying transatlantic alliance, a geopolitical cornerstone that has been an article of faith for U.S. and Western European governments since the end of World War II.

America’s jittery European partners are increasingly worried that the erosion could prove terminal.

Their immediate concern, and the main catalyst for Germany’s startling defense policy U-turn, is the war in Ukraine.

The conflict raises the prospect that European democracies could find themselves on their own in trying to prevent Russian President Vladimir Putin from securing the main aims of his 2022 invasion and going on to threaten other neighboring states. 

The transatlantic tension is not new. It has been building for years amid Washington’s frustration at being expected to carry most of the burden within the security alliance, while its allies were spending a relative pittance on defense. Few of them even reached the agreed NATO minimum of 2% of their gross domestic product.

But Mr. Putin’s unprovoked attack on Ukraine jolted those allies into defense spending hikes. Most have now reached the 2% target, and some, like Poland on Ukraine’s border, are well above it.

Until the other day, Germany remained a glaring exception. 

It is Europe’s largest economy, but has long had only a rudimentary military force. The legacy of Adolf Hitler’s war of conquest has weighed heavily on German memories.

On top of that, Germany’s fiscal conservatism precluded major defense investments. The country’s constitution includes a limit on government borrowing.

All of that changed last week.

The center-right politician in line to become Germany’s next chancellor, Friedrich Merz, shattered both political taboos. He secured parliamentary approval for a $500 billion fund to make “whatever it takes” investments in defense and infrastructure, and an exemption from the legal debt limit.

Mr. Merz was acting with one eye on what he called Moscow’s “war of aggression against Europe.”

But his other eye was on Washington.

No sooner had the polls closed in last month’s national election than Mr. Merz, long a strong supporter of the transatlantic alliance, confessed that he now worried that the Trump administration was “largely indifferent to the fate of Europe.”

Mr. Merz's “absolute priority,” he said, was to “to strengthen Europe as quickly as possible so that, step by step, we can really achieve independence from the USA.”

The problem for Germany – and countries such as Britain, France, and Poland, which are also seeking a Europe-wide leap in military preparedness – is that “step by step” may not be an option.

Washington’s indifference to Europe has been clear for several weeks. It has been evident in the approach that President Donald Trump has taken to Ukraine peace talks so far, prioritizing improved relations with Moscow and leaving European allies largely on the sidelines.

But the leaked Yemen chat transcript suggests that key administration figures, especially Vice President JD Vance, are not merely indifferent to Washington’s European allies.

They are hostile.

Mr. Vance questioned whether the strikes against Houthi forces in Yemen were merited, since their attacks on Red Sea shipping had a negligible effect on U.S. trade and mostly impacted Europe. Though aware Mr. Trump greenlit the attack, he said he wasn’t “sure the president is aware how inconsistent this is with his message on Europe.”

At that point, Defense Secretary Pete Hegseth chimed in: “I fully share your loathing of European freeloading. It’s PATHETIC.”

If “freeloading” – Europeans’ long-standing reluctance to shoulder the costs of defending their continent – is the critical issue, then Germany’s policy shift is the latest sign that they are fully aware of their new burden.

They had hoped to convince Mr. Trump that they accepted this burden, that change was underway, and that it was in both Europe’s and America’s interest to make the change as effective and disruption-free as possible.

That remains essential. The hard truth is that most European military forces are understaffed, their equipment aging.

The allies know that without America’s muscle – its airpower, air defense, intelligence and coordination capabilities – it will be some time before they are able to monitor compliance with any Ukraine peace deal, as they aspire to do. Providing a credible bulwark against future Russian aggression is out of the question.

Europe’s reliance on an American military “backstop” made sense so long as the allies on both sides of the Atlantic shared a broadly similar view of the world, especially the view that Mr. Putin’s autocratic Russia was the main threat to their security.

But it is no longer clear that Mr. Trump believes that. Should that be the case, the Europeans will not only find themselves alone.

They will have to adapt to this new reality without the resource they need most of all: time.