Ukraine Worries About Losing Its Biggest Weapon: U.S. Military Aid

In the two years since Russia launched its full-scale invasion, Ukraine has had its back to the wall many times, in many forms: fighting with Molotov cocktails and guns handed out to the population, coping with blackouts and fleeing refugees. But there was always the prospect of more American aid on the horizon.

That support was critical, analysts and leaders in Kyiv say. The United States has provided about half of the foreign military assistance to Ukraine’s arsenal, roughly $47 billion.

But this week leaders in Kyiv have waited anxiously to see if that lifeline will come to an end, as a stalemate between lawmakers in the United States Congress threatens to end, for now, American support for the war against Russia.

A measure that would allow American arms to flow to Ukraine, Israel and Taiwan and fund border security was defeated in a Senate vote on Wednesday amid growing Republican opposition and deep division on Capitol Hill.

After the vote, the Senate majority leader, Chuck Schumer, said he would try an alternate path, pushing a vote on foreign military aid stripped of the more contentious measures on immigration. Democrats and Republicans alike expressed some optimism for the new measure, but by Wednesday evening, lawmakers were bogged down again. Mr. Schumer recessed the Senate until noon on Thursday.

But even if the Senate approves the aid, its fate in the House remains uncertain.

Ukraine’s army would not suddenly be overwhelmed, analysts say, but the degradation of its forces would be inexorable. European nations lack American-level stockpiles of weapons and ammunition, and would be unlikely to fill the gap, military analysts say.