Later, the fleet in the Indian Ocean was then gradually reduced to little more than a convoy escort force as other commitments called for the more modern, powerful ships. In May 1942, the Eastern Fleet supported the invasion of Madagascar, Operation Ironclad. It was aimed at thwarting any attempt by Japanese vessels to use naval bases on the Vichy French controlled territory. During the invasion, vessels of the Eastern Fleet were confronted by vessels of the French Navy and submarines of the Imperial Japanese Navy.