Partly to blame for the War against the Bolsheviks not being brought to a conclusion with his idiotic invasion of Greece, which the Italians - as per their habit - made a horse's arse of, which then required Hitler to move divisions into Greece to plug the gap Mussolini created, which would otherwise have been filled by British divisions, threatening the entire war. This put the timetable for Barbarossa back by almost a month, which turned out to be utterly crucial as it left the Germans fighting into the Winter season - something that would have been avoided had the operation gone ahead in May, as originally planned.
Still, Benito was a lion compared to the Chihuahuas we have as 'leaders' in European governments these days.