billion ceiling on defense expenditure in fiscal year 1950. The Joint Chiefs estimated that in the event of a war, this would reduce the United States reaction to a strategic bombing offensive from the United Kingdom. The Joint Chiefs of Staff divided the $14.4 billion between the three services, giving $4.834 billion to the Army, $4.624 billion to the Navy, and $5.025 billion to the Air Force. This meant that the air force would have to cut back to just 48 groups. Vandenberg convened a senior officers' board chaired by General Joseph T. McNarney to determine an appropriate structure. It decided to reduce the Strategic Air Command to 14 bombardment groups. Its commander Lieutenant General Curtis LeMay, stated that the atomic mission required four groups of bombers, which he said should be equipped with B-36s. The B-36 could cover 97 percent of targets in the Soviet Union from bases in North America, and in the conventional role it could carry of bombs over medium distances. He endorsed a proposal to improve the performance of the B-36 by adding twin jet pods (B-47 jet engines). Of the remaining ten bombardment groups, five would be equipped with B-50s, two with the new B-47s, and three with B-29s. The B-36 program actually benefited from the cutbacks, because $269,761,000 was recouped from the cancellation of orders for other aircraft. LeMay also recommended that the Boeing B-54, an improved version of the B-50, be canceled and the funds used to purchase 36 more B-36s and five more B-47s. Forrestal signed off on this recertification of funds in March 1949. That month the board also recommended that B-36 acquisition be limited to what was required for four groups, after which production would be switched over to the B-52. Aircraft carriers The Navy had no theoretical framework with which to develop a post-war strategy. Between 1890 and 1945 its doctrine had been based on the teachings of Alfred Thayer Mahan, who stressed the importance of control of the sea in securing the lines of communication through which maritime commerce traveled and argued that the main objective of a Navy was the destruction of the enemy's battle fleet. But the Soviet Union had only a small navy, and as a Eurasian power, it was not dependent on maritime trade, and thus was immune to the effects of a naval blockade. Being in third place for funding behind the