For Harris, Promises to Ukraine Prove Harder to Make Amid G.O.P. Resistance

When Vice President Kamala Harris flew to Germany for the Munich Security Conference last year, she made an unequivocal promise. “The United States,” she said, “will continue to support Ukraine, and we will do so for as long as it takes.”

When Ms. Harris returned to the same forum and took the same stage this past week, her message sounded similar but there was one important difference. “You have made clear that Europe will stand with Ukraine,” she told the gathered leaders, “and I will make clear President Joe Biden and I will stand with Ukraine.”

Not the United States this time, but she and Mr. Biden. It was a personal pledge that she could make on behalf of herself and her president, but she could not be so definitive about her country. For those watching for clues, it was a seemingly subtle shift in wording that spoke volumes.

Neither Mr. Biden nor Ms. Harris can promise with any degree of certainty anymore that America really is in the fight with Ukraine for the long haul. House Republicans are blocking $60 billion in security aid even as Ukrainian troops short of ammunition and weaponry just have had to withdraw from the city of Avdiivka. And an election less than nine months away could return to office former President Donald J. Trump, no friend of Ukraine or NATO but an open admirer of President Vladimir V. Putin of Russia.

Ms. Harris was not trying to shirk from the fight during her trip to Munich — quite the opposite, she was doing everything she could to reassure nervous Ukrainians and Europeans of her administration’s resolve. But the reality is that the political uncertainty back home has destabilized the multinational coalition backing Ukraine just days from the second anniversary of Mr. Putin’s invasion.

President Volodymyr Zelensky of Ukraine gave voice to the anxiety. “The key issue for us now is the preservation of principal American support,” he said at a joint news conference with Ms. Harris. “Ukraine and all our warriors need and await the respective positive vote regarding the assistance package, and I think everybody understands how much depends on this single voting procedure.”