If there is one constant in U.S. political history, it is that presidents frequently make oversights, miscalculations, and even egregious mistakes in handling national security. Vietnam remains the ultimate case in point: a striking example of a talented and successful politician—in this case, President Lyndon B. Johnson—recklessly sending hundreds of thousands of U.S. service members into combat.
Historians and social scientists have spilled a great deal of ink trying to explain what has led U.S. presidents to misuse their power as commander in chief. For many generations of academics, the answer to the question of what went wrong in Vietnam and other failed wars lay in the ideological orthodoxies that blinded elected officials to the facts on the ground. In both Vietnam and Korea, historians argued, the “domino theory” was to blame, as it predicted that if one small country fell to communism, others would follow.
New Left historians in the 1960s and 1970s reached very different conclusions. In their work, ideology had little to do with it; rather than seeking to protect democracy abroad, administrations instead went to war to please interest groups, appease congressional committees, feed the budgets of defense contractors, or secure territorial control and valuable
