Who was to blame for starting the Cold War？ For nearly a generation after World War II, American historians generally agreed that the suspicious and grasping Soviets were almost solely responsible. This "Orthodox"(正统的) appraisal fitted comfortably with the traditional view of the United States as a God-blessed land with an idealistic foreign policy. But in the 1960s another interpretation began to flower, powerfully reinforced by an objection against what Americans were doing in Vietnam. People who held this view attempted to reverse the orthodox view. They argued that the Soviets had understandably defensive intentions at the end of World War II and that the United States had behaved aggressively and irresponsibly. Some of these critics pointed an accusing finger at Truman. They declared that he had abandoned Roosevelt' s conciliatory (调和的) approach and adopted a bullying attitude, emboldened by American's atomic monopoly. The more radical of those people like the Kolkos found the roots of American aggression before Truman's time in long-standing policies of economic expansion.
In the 1970s a "neoorthodox" interpretation emerged. Historians of this school, like John L. Gaddis, still place most of the blame for the Cold War on the Soviet Union, but they admit that American policies helped worsen the conflict. They also note how the constraints of domestic politics and the miscalculations of American leaders led a nation in search of international security into dangerous Cold War.
This historical debate over the origins of the Cold War has compelled the recognition that the United States did have vital interests at stake in postwar diplomacy, and that policymakers pursued those interests with eagerness. But is self- interest necessarily immoral？ Is security a one-way street？ Can the blame ever be exclusively with one side in a complex international dispute？
A title that would best express the main idea of the passage would be______.

A. The Origins of the Cold War
B. Who Should be Blamed
C. A Complex International Dispute
D. American Foreign Policy