Planning for Japan left the wrong escort balance

One explanation for the Royal Navy's limited sloop program is that it could not obtain extra funding and had to prioritize the enemy it expected to fight. Japan presented an immediate confrontation, while Germany and Italy appeared to be threats whose wars lay further ahead. For a Japanese war, British planning emphasized carriers, cruisers, and battleships. Holding Singapore was expected to block Japanese access to the Indian Ocean and protect trade routes running away from Japan, reducing the apparent need for large numbers of convoy escorts. When the European war came first, Britain had to change its force priorities. Stopping carrier construction during that adjustment created another problem because naval air power remained useful against Germany and Italy.