 The lack of time between the bombings led Martin J. Sherwin to speculate that the second bombing was "certainly unnecessary", and Bruce Cumings that it was "gratuitous at best and genocidal at worst".Fredrik Logevall argued that President Harry S. Truman hoped that after the first atomic bomb, Japan would capitulate soon, but "the swift capitulation of Japan was crucial in order to preempt a Soviet military move into Asia" that Truman had requested.On the other hand, Robert James Maddox argued that more than one bomb was necessary because military hard-liners in the Japanese government refused even to admit that the single Hiroshima bomb was atomic.