The specter of chemical warfare has risen in Ukraine, shattering a fragile peace and sending shockwaves through the international community.

The United States on Wednesday, May 1, accused Russia of deploying chloropicrin, a banned chemical weapon, against Ukrainian troops, marking a dramatic escalation in the ongoing conflict.

This chilling development comes alongside a crippling new sanctions package aimed at crippling Russia’s war machine.

“This is a horrific violation of international law,” declared a grim-faced Secretary of State Anthony Blinken. “Russia’s use of chemical weapons is a barbaric act that threatens not just Ukraine, but the global order we have strived to maintain for decades.”

Chloropicrin, a choking agent with a gruesome history in World War I, can cause severe respiratory problems, vomiting, and even death.