A better-fortified Singapore might still fall, and its survival would depend on several wartime conditions. The comparison with Malta has limits because supplies for Singapore would largely come from India. Holding Singapore would itself restrict Japan's opportunities to establish a stronger presence in the Indian Ocean. Torpedo boats, sloops, and submarines operating from the base could add defensive depth along the supply approach. Heavy guns with suitable ammunition would complicate a siege, although neither secure supply nor freedom from siege is guaranteed in the scenario.
Notable Point · 1:09:57-1:12:10
Singapore's supply routes and the limits of the Malta comparison
A fortified Singapore would draw supplies from India, and holding it could restrict Japanese access to the Indian Ocean while local naval forces protected the approach.