Why a major Italian surprise attack would meet layered defenses

Extra Italian capital ships would prompt stronger British defenses, while submarines, destroyers, aircraft, and fleet units already guarded Malta and Alexandria against the kind of harbor attack Britain itself planned to conduct.

Question

Could a strengthened Italian fleet launch a successful surprise attack on Malta or Alexandria when Italy entered World War II?

Short answer

It could try, but the changed threat would bring stronger layered defenses and a serious risk that British submarines, aircraft, destroyers, and fleet units would catch it.

Notes

A larger Italian battle fleet would not approach Malta or Alexandria in a strategic vacuum. Britain would reinforce the threatened anchorages as the balance changed, using destroyers, submarines, aircraft, and capital ships as layered warning and combat forces. Royal Navy submarines in particular could serve as an offshore defensive screen. Because British doctrine included surprise attacks on enemy fleets in harbor, British planners were unusually alert to the same method being used against them.