MacArthur spent 45 minutes after the briefing explaining his reasons for choosing Inchon. He said that, because it was so heavily defended, the North Koreans would not expect an attack there, that victory at Inchon would avoid a brutal winter campaign, and that, by invading a northern strong point, UN forces could cut off KPA lines of supply and communication. Sherman and Collins returned to Washington, D.C., and reported back to Secretary of Defense Louis A. Johnson. The Joint Chiefs of Staff approved MacArthur's plan on 28 August. President Truman also provided his approval.