No island was strategically placed because no island was created and placed anywhere. However, the location of some islands serve a purpose better due to their location. Hawaii is probably one of them. Since they are located far out from the United States in the Pacific Ocean, they can spot ships easily. The Navy also has a place to dock them.
Instead of having to travel further to the United States, Hawaii is a few hours away from California and the Navy can save some time by docking their boats there. It is easier to dock the boats on an island. The strategy involved placing the military base on Hawaii and making sure it could be used to the best benefit of its purposes.