Sōryū and Hiryū were critical assets for the Indian Ocean raid, and the force would have been markedly weaker without them. The point extends to the wider campaign, since one or both carriers appeared in every serious carrier-air-power operation between Pearl Harbor and Midway. Their importance came from sustained availability and operational tempo rather than one famous morning alone. The pair stood at the center of Japan's early-war maritime offensive.
Notable Point · 1:02:01-1:02:43
The Indian Ocean raid depended on Sōryū and Hiryū
Removing either carrier would have weakened the Japanese Indian Ocean raid and nearly every major carrier operation between Pearl Harbor and Midway.