 This course of events disturbed Lieutenant General Frederick Weyand , commander of U.S. forces in III Corps , which included the Capital Military District . Weyand , a former intelligence officer , was suspicious of the pattern of communist activities in his area of responsibility and notified Westmoreland of his concerns on 10 January . Westmoreland agreed with his estimate and ordered 15 U.S. battalions to redeploy from positions near the Cambodian border back to the outskirts of Saigon . When the offensive did begin , a total of 27 allied maneuver battalions defended the city and the surrounding area . This redeployment may have been one of the most critical tactical decisions of the war . 
