The effect of the situation in the Balkans in February-May 1941

As an aside, the military and political situation in the Balkans in February through May 1941 may have affected the outcome of the war. The critical incident was the coup by the Serbians in Yugoslavia. That probably brought in a more immediate and decisive German intervention in the Balkans that delayed the attack on Russia by a month. If the Barbarrosa could have taken place a month earlier, Moscow might have been taken with incalculable affect on the outcome of the war. Seemingly small and obscure events can have great effects.