Could the right plan have won it for Italy?

[T. A. Gardner]

I agree, with one change. Italy enters the war only when the US and Britain launch their first large and successful offensive. That's when Italy should jump in. If they finished a carrier or two, they might even offer some of their fleet to support Allied operations in the Pacific. Giving the Allies access to basing in East Africa wouldn't hurt either.

The idea here is Italy tries to get the Allies to do infrastructure work in their territories so they get to retain those improvements when the war ends.

In the interim, Italy plays both sides. They get the Allies to offer to supply arms and equipment they lack for their military in exchange for access while stringing the Germans along with allowing their merchants to shelter in Italian ports as a neutral. They pass on intelligence to the Allies and Germans both. Importing and selling scarce resources to Germany would be useful too. For example, importing rubber would get them cash. The Allies might trade oil for Italy agreeing not to supply certain stuff to Germany as an alternative.

That way both sides might be actively trying to woo them into actively joining the war.

[Markus Becker]

Italy enters the war only when the US and Britain launch their first large and successful offensive.

Operation Torch: Anglo American landings in Italy which at the same time declares war on Germany.

The Germans never saw the actual one coming. If Mussolini keeps his mouth open and loudly proclaims his intention to remain neutral this one could be a strategic surprise too.

Regarding trade with both sides, machine tools would be high on my shopping list. Italy had great engineers and craftsmen but designed and made some good stuff but not in the numbers needed.