Ukrainian forces don't have enough artillery to battle Russia. A key withdrawal Saturday shows that

Dwindling ammunition threatens Ukraine’s hold on the 1,000-kilometer (620-mile) front line under withering assault by Russian artillery. Defensive lines are in jeopardy.

Ukrainian forces withdrew from the city of Avdiivka in the Donetsk region on Saturday after daily Russian onslaughts from three directions for the last four months.

Avdiivka was a stronghold for Ukrainian positions deeper inside the country, away from Russia. A frontline city ever since Russia first invaded Ukraine in 2014, the fortified settlement with a maze of trenches and tunnels served to protect important — less strengthened — logistical hubs further west.

Its seizure boosts Russian morale and confirms that the Kremlin’s troops are now setting the pace in the fight, to the dismay of Ukrainian forces who have managed only incremental gains since their counteroffensive last year.

CONGRESSIONAL INACTION

The Biden administration linked the loss of Avdiivka to Congressional inaction on $60 billion in military aid for Ukraine.

President Joe Biden said he told Ukrainian President Volodymyr Zelenskyy in a Saturday phone call after Ukraine announced it was withdrawing troops from Avdiivka that he remained confident that the U.S. funding would eventually come through. But, when reporters asked if he was confident a deal could be struck before Ukraine loses more territory, Biden responded: “I’m not.”

DWINDLING SUPPLIES

The Associated Press interviewed over a dozen commanders, including heads of artillery units, in the war’s most intense combat zones in the weeks ahead of Avdiivka’s fall. They said shortages, which have always plagued Ukrainian forces since the full-scale invasion, grew acute last autumn.

Dwindling supplies of Western-supplied long-range