Why was Stalin not surprised that the United States had the atomic bomb?

The United States government was deeply penetrated with Soviet spies. Even one of the senior scientists on the Manhattan Project itself was a communist agent who regularly passed information along to Moscow. Stalin knew all about it. Michael Montagne Stalin holded a meeting with USSR famous scientists in 1942 , researched A- bomb ! USSR knowed A-bomb by Britain USSR understanded that make A-bomb by USA