Still, the difficulties presented by the Marianas were daunting. Fuel and supplies would be brought in by sea, but the maritime umbilical cord was long—5,800 miles from San Francisco Bay—and the B-29s would have to compete with hundreds of other Allied military units for scarce shipping and other resources. The heavily loaded bombers would operate from bases that had not yet been built, on islands where enemy holdouts were still fighting in the hills. From Saipan, Tinian, or (especially) Guam, targets in Japan lay near the outer limit of the B-29’s operating radius.
