In an open letter that Roberts circulated online via a Ukrainian friend, Roberts claims he accompanied the Ukrainian army’s elite 3rd Assault Brigade when, around two weeks ago, it deployed to Avdiivka—a former Ukrainian stronghold in eastern Ukraine—to cover the withdrawal of the city’s garrison.

Roberts doesn’t mince words. The Ukrainians retreated from the ruins of Avdiivka after a fierce, four-month defense against a Russian force 10 times its size because it ran out of ammunition. And it ran out of ammunition because Republicans in the U.S. Congress have blocked U.S. aid to Ukraine.

“On the ground in Avdiivka, we felt the results of current American politics with full force,” Roberts writes.

We are accustomed to fighting with less artillery than the Russians. We have already developed clever ways of using precision fire to counter Russian artillery. Our artillery soldiers use their American-provided weapons efficiently and effectively to batter the second-largest military in the world so that our assaulters have cover while they pierce like needles to rapidly cut the Russian force’s critical arteries. This week, our ammunition has effectively stopped. Our precision scalpel cannot cut.

Avdiivka turned into an attrition trap for the Russians. At the likely cost of a few thousand casualties, the Ukrainian garrison in the industrial city—anchored by the army’s 110th Mechanized Brigade—killed or maimed perhaps 30,000 Russians from the 2nd and 41st Combined Arms Armies.

A Ukrainian retreat wasn’t inevitable. No, it was a choice by what Roberts describes as a “super-minority” in the U.S. Congress.

It’s a veiled reference to Republican Speaker of the House Rep. Mike Johnson and his far-right allies in the U.S. House of Representatives, who since October have refused to bring to a vote Pres. Joe Biden’s proposal to spend another $60 billion on aid to Ukraine. A proposal that already has passed the U.S. Senate with strong bipartisan support.

Johnson’s blockade of aid to Ukraine continued as Republican ex-president Donald Trump recently said he told America’s European allies he’d let Russians do “whatever the Hell they want.”

“I can tell you that here in Avdiivka, we felt the result of Congress’ actions to defund Ukraine,” Roberts writes.