Learning from Taranto and American exercises

Similarity between Pearl Harbor, Taranto, and American exercises does not by itself establish that Japan copied an entire plan. The argument for a longer Japanese planning history allows later operations and exercises to refine an existing concept. Intelligence about another navy's methods can improve a plan without supplying its original purpose. Directly repeating a successful exercise attack would also assume that the defenders had failed to correct the weakness it exposed. That expectation of defensive adaptation is part of the criticism of simple copying accounts.