The B-29 had only recently rolled off the assembly line a few months earlier, and production was already ramping up rapidly.
It was the only bomber capable of reaching mainland Japan. But even having the aircraft didn't make bombing Japan easy.
To make it possible, the U.S. military had launched Operation Matterhorn. The strategy: use Chengdu in China as the forward base—2,340 km from Kyushu. B-29s would refuel and arm up in Chengdu, fly to bomb Japan, then return to base.
But every drop of fuel and every ton of bombs loaded in Chengdu had to be airlifted from India by the China-U.S. Allied Transport Corps—over the Hump Route. According to later estimates, eighteen tons of supplies had to be flown in just to drop one ton of bombs on Japan. That logistics burden drastically cut into U.S. aid to China.
"Eighty percent of the Hump Route's capacity was used for bombing Japan. Aid to China was reduced to the bare minimum…"
