Why San Diego was a harder Japanese target

Would Japan still have struck if the U.S. Pacific Fleet had stayed at San Diego?

A San Diego strike would have been much harder because of the full-Pacific transit, tanker demand, return journey, and more obstructed attack approaches.

The answer stresses distance and geography rather than assuming any U.S. base was equally vulnerable. A strike on San Diego would require the Japanese carrier force to cross the full Pacific with much more tanker support and then return, while the harbor's surrounding terrain created additional approach obstacles. Pearl Harbor's mid-ocean position and shallow-water defenses presented a different, more manageable problem.