Operation Matterhorn was developed by Brig. Gen. Kenneth B. Wolfe in October 1943 for implementation by the XX Bomber Command. Wolfe drew from an initial plan termed "Setting Sun" based on an outline drawn by President Franklin D. Roosevelt at the Casablanca Conference and from a counter-plan offered by Gen. Joseph Stilwell called "Twilight". (The primary difference between the two was that Chennault proposed that the B-29s be permanently based in India and forward-based in China.) The forward airbases in China would be self-sustaining, supplied out of India by flying materiel over the Hump using B-29s, a fleet of C-109 fuel tankers, 20 C-87 transports, and three C-46 bomber support squadrons. Under Setting Sun, the forward bases were to be in Guangxi in southern China, but because of intense Japanese pressure against the forces commanded by Stilwell and Gen. Claire Chennault, the Matterhorn plan moved the bases farther inland to Chengdu.