Why did Truman doubt Stalin’s motives? What did Truman think Stalin might do?

Truman was highly suspicious of STalin's motives. He was much less trusting than Roosevelt, who had relied on the theme of mutual cooperation to achieve his objectives. Stalin refused to reduce the size of the Red Army, the biggest in theworld.

President Harry Truman records his impressions of meeting Stalin. On this day in 1945, President Harry S. ... Truman hoped to get the Soviets to join in the U.S. war against Japan. In return, Stalin wanted to impose Soviet control over certain territories annexed at the beginning of the war by Japan and Germany.

Explanation:

four sitting presidents have been assassinated while in office but the first was abraham lincoln,

besides the fact that abraham lincoln abolished slavery, and greatly benefit black people, he had a heavy impact of the definition of what democracy was, and should be.