In 1948, Stalin edited and rewrote sections of "Falsifiers of History", published as a series of "Pravda" articles in February 1948 and then in book form. Written in response to public revelations of the 1939 Soviet alliance with Germany, it focused on blaming Western powers for the war. He erroneously claimed that the initial German advance in the early part of the war was not a result of Soviet military weakness, but rather a deliberate Soviet strategic retreat. In 1949, celebrations took place to mark Stalin's seventieth birthday (although he was 71 at the time,) at which Stalin attended an event in the Bolshoi Theatre alongside Marxist–Leninist leaders from across Europe and Asia.