During the negotiations for the Pact of Steel between Germany and Italy, Italian Under Secretary for War Carlo Favagrossa determined that Italy would not be ready for a war until 1943, This was due to the fact that the substantially weak Italian industry did not equal more than 15% of that of France or of Britain in militarily critical areas such as automobile production. This was made clear to the German delegation who then signed the Pact.
But as we all know, Hitler invaded Poland in 1939, beginning the European theatre of World War II. Italy would declare war on France and Britain the following year.
But I've found this idea very intriguing s I want you to create a scenario in which the European theatre of World War II is delayed until 1943. Note that I said the European theatre only. This is because I am not sure if a late European war would affect events in the Pacific or not.