sentences:  Greece and Turkey were strategic allies important for geographical reasons as well, for the fall of Greece would put the Soviets on a particularly dangerous flank for the Turks, and strengthen the Soviet Union's ability to cut off allied supply lines in the event of war.To pass any legislation Truman needed the support of the Republicans, who controlled both houses of Congress.The chief Republican spokesman Senator Arthur H. Vandenberg strongly supported Truman and overcame the doubts of isolationists such as Senator Robert A. Taft.