Officials have suggested that the pause in weapons shipments and intelligence sharing could be relatively short-lived if Ukraine’s president bends to White House demands.
On the battlefields of Ukraine and western Russia, a stalemated war has ground on, with Ukrainian troops defending against Russian progress that can be measured sometimes in mere yards. The cost has been heavy casualties on both sides.
President Trump’s decision this week to pause military assistance and intelligence sharing could reorder the battlefield, either halting the fight or potentially giving Russia a decisive advantage.
With help from Europe, both with arms and intelligence support, Ukraine could continue the fight through the summer without additional American aid. But the loss of one of its most important benefactors will make it easier for Russia to assault Ukrainian lines of defense, analysts say.
“Despite the disadvantage in munitions and forces, Ukrainians have done admirably well in preventing any kind of Russian breakthrough,” Seth G. Jones, a senior vice president with the Center for Strategic and International Studies, said in an interview.
Trump administration officials have suggested that the pause in support could be relatively short-lived if Ukraine’s president, Volodymyr Zelensky, bends to the demands of the White House. Mr. Trump, in his address to Congress on Tuesday night, said he appreciated that Mr. Zelensky had said earlier in the day that he was ready to “come to the negotiating table.”
For now, the Trump administration is putting maximum pressure on Ukraine, and relatively little on Russia’s president, Vladimir V. Putin, or the Russian military, which has continued to attack Ukrainian cities. If the United States is seen as a completely unfair broker of peace, Ukraine could look for ways to continue the fight with the support of Europe.