The Spy War: How the C.I.A. Secretly Helps Ukraine Fight Putin

Nestled in a dense forest, the Ukrainian military base appears abandoned and destroyed, its command center a burned-out husk, a casualty of a Russian missile barrage early in the war.

But that is above ground.

Not far away, a discreet passageway descends to a subterranean bunker where teams of Ukrainian soldiers track Russian spy satellites and eavesdrop on conversations between Russian commanders. On one screen, a red line followed the route of an explosive drone threading through Russian air defenses from a point in central Ukraine to a target in the Russian city of Rostov.

The underground bunker, built to replace the destroyed command center in the months after Russia’s invasion, is a secret nerve center of Ukraine’s military.

There is also one more secret: The base is almost fully financed, and partly equipped, by the C.I.A.

“One hundred and ten percent,” Gen. Serhii Dvoretskiy, a top intelligence commander, said in an interview at the base.

Now entering the third year of a war that has claimed hundreds of thousands of lives, the intelligence partnership between Washington and Kyiv is a linchpin of Ukraine’s ability to defend itself. The C.I.A. and other American intelligence agencies provide intelligence for targeted missile strikes, track Russian troop movements and help support spy networks.

Adam Entous is a Washington-based investigative correspondent and a two-time Pulitzer Prize winner. Before joining the Washington bureau of The Times, he covered intelligence, national security and foreign policy for The New Yorker magazine, The Washington Post and The Wall Street Journal.

Michael Schwirtz is an investigative reporter with the International desk. With The Times since 2006, he previously covered the countries of the former Soviet Union from Moscow and was a lead reporter on a team that won the 2020 Pulitzer Prize for articles about Russian intelligence operations.