in 1942, barbour was appointed to a position in the office of the coordinator of inter-american affairs, council of national defense, probably as a direct result of his previous connections with the rockefeller foundation (the council of national defense had been set up by the roosevelt administration in 1940 and nelson rockefeller had been appointed as its inaugural director). early the same year, (16 february 1942), barbour enrolled for the draft. once the us entered the war, he joined the us army and rose from private to captain between 1942 and 1946. after attending officer's school he was attached to general eisenhower's staff at supreme hq in london.