Throughout American history, Presidents have dispatched armed forces abroad to protect the lives and property of United States citizens as well as American security interests. However, these military operations usually were limited in scope and duration, were conducted against relatively defenseless nations, and did not involve major powers. Thus, there was little opportunity to test the President's constitutional authority to send armed forces abroad without prior congressional authorization or a DECLARATION OF WAR. For various reasons, the KOREAN WAR did not furnish the occasion to test President HARRY S. TRUMAN'S constitutional powers. The Vietnam War (1965?1973) was the first modern undeclared war that provided the opportunity to test the President's authority as COMMANDER-IN-CHIEF.
During the Vietnam War numerous litigants challenged the President's authority to initiate and conduct military hostilities without a congressional declaration of war or other explicit prior authorization. Such litigants denied that the GULF OF TONKIN RESOLUTION constituted authorization. Despite these challenges, the federal courts exhibited extreme caution in entering this twilight zone of concurrent power. The federal judiciary's reluctance to decide WAR POWERS controversies reveals a respect for the constitutional SEPARATION OF POWERS, an appreciation for the respective constitutional functions of Congress and the President in FOREIGN AFFAIRS, and a sense of judicial self-restraint. Nevertheless, toward the end of the Vietnam War, several lower federal courts entered the political thicket to restore the constitutional balance between Congress and the President.
Despite factual variations, the Vietnam War cases can be classified into four broad categories. One federal district court asserted categorically that the complaint raised a POLITICAL QUESTION beyond the court's JURISDICTION. A second agreed that the President's authority to conduct military activities without a declaration of war posed a nonjusticiable political question, but proceeded to determine whether the President had acted on his own authority, pursuant to, or in conflict with either the expressed or implied will of Congress. Courts in the third category concluded that the political question doctrine did not foreclose them from inquiring into the existence and constitutional sufficiency of joint congressional-presidential participation in prosecuting the war...