Notified that British aid to Greece and Turkey would end in less than six weeks, and already hostile towards and suspicious of Soviet intentions, because of their reluctance to withdraw from Iran, the Truman administration decided that additional action was necessary. With Congress solidly in Republican hands, and with isolationist sentiment strong among the U.S. public, Truman adopted an ideological approach. In a meeting with congressional leaders, the argument of "apples in a barrel infected by one rotten one" was used to convince them of the significance in supporting Greece and Turkey. It was to become the "domino theory". On the morning of March 12, 1947, President Harry S. Truman appeared before Congress to ask for $400 million of aid to Greece and Turkey. Calling on congressional approval for the United States to "support free peoples who are resisting attempted subjugation by armed minorities or by outside pressures," or in short a policy of "containment", Truman articulated a presentation of the ideological struggle that became known as the "Truman Doctrine." Although based on a simplistic analysis of internal strife in Greece and Turkey, it became the single dominating influence over U.S. policy until at least the Vietnam War.