On the first day of the war the US airforce shot down seven North Korean aircraft. The US immediately acheived overwhelming air superiority in the war. US B-29 strategic bombers destroyed all of the strategic targets that existed in North Korea. When the Chinese intervened on the side of the North Korean, their MIG 15 put the US at a temporary disadvantage, as the MIG 15 was superior to the F-80 then being flown by the US. F-86 were rushed to Korea and they quickly reestablished US air superiority. The US forces were not permitted to pursue Chinese forces across the Chinese border and this gave the Chinese a tactical advantage.