At the end of Chapter 23, what did Patton know about a top-secret policy instituted by General George Marshall?

Patton knew that a top-secret policy instituted by General George Marshall and approved by Roosevelt and Truman abandoned all American and British POWs who were captured by the Russians at the end of the war. Patton believed that Truman allowed more than 20,000 American POWs to remain in Russian hands.