Europe, Dazed by Trump, Confronts Hard Choices in Ukraine

For years, European leaders have fretted about reducing their dependence on a wayward United States. On Monday, at a hastily arranged meeting in Paris, the hand-wringing gave way to harried acceptance of a new world in which Europe’s most powerful ally has begun acting more like an adversary.

President Trump’s plan to negotiate a peace settlement in Ukraine with President Vladimir V. Putin of Russia, with neither the Ukrainians nor Europeans invited to take part, has forced dazed leaders in capitals like Berlin, London and Paris to confront a series of hard choices, painful trade-offs and costly new burdens.

Already on the table is the possibility that Britain, France, Germany, and other countries will deploy tens of thousands of troops to Ukraine as peacekeepers. European governments are affirming the need for major increases in their military budgets — if not to the 5 percent of gross domestic product demanded by Mr. Trump, then to levels not seen since the Cold War days of the early 1980s.

“Everybody’s hyped up at the moment, understandably,” said Lawrence Freedman, emeritus professor of war studies at King’s College London. “What is clear is that whatever happens, Europe will have to step up.”

That could put its leaders in a difficult spot. While public support for Ukraine remains strong across Europe, committing troops to potentially dangerous duty on Ukrainian soil could quickly become a domestic political liability. Estimates on the size of a peacekeeping force vary widely, but under any scenario, it would be an extremely expensive undertaking at a time of straitened budgets.

President Emmanuel Macron of France, who first floated the idea of a peacekeeping force last year — to widespread skepticism in Europe — has been weakened since his decision to call parliamentary elections last summer backfired and left him with a fragile government.