It all came from the United States, over the course of five years and part of about $4 billion in military and security assistance designed to counter the Moscow-backed separatist rebellion in eastern Ukraine’s Donbas region.

“It’s helped us significantly,” Bondar said. In the Ukrainian colonel’s view, simply providing an army with modern equipment is in itself a deterrent to an aggressor.

This was the sort of aid that President Trump froze over the summer as he sought to pressure President Volodymyr Zelensky into announcing investigations of former vice president Joe Biden and his son Hunter — although no known evidence of wrongdoing by the Bidens has emerged.

And that freeze is now at the heart of the House impeachment hearings.