The very heavy bomber still suffered mechanical problems that grounded some aircraft and forced others to turn back before dropping their bombs. Even those B–29s that reached the target area often had difficulty in hitting the objective, partly because of extensive cloud cover or high winds. Larger formations could have helped compensate for inaccurate bombing, but Saunders did not have enough B–29s to dispatch large formations. Also, the Twentieth Air Force periodically diverted the Superfortresses from strategic targets to support theater commanders in Southeast Asia and the southwestern Pacific. For these reasons, the XX Bomber Command and the B–29s largely failed to fulfill their strategic promise.