according to the constitution how can the united states declare war
Declaration of war by the United States For the United States, Article One, Section Eight of the Constitution says "Congress shall have power to ... declare War." However, that passage provides no specific format for what form legislation must have in order to be considered a "declaration of war" nor does the Constitution itself use this term. In the courts, the United States Court of Appeals for the First Circuit, in Doe v. Bush, said: "[T]he text of the October Resolution itself spells out justifications for a war and frames itself as an 'authorization' of such a war."[1] in effect saying an authorization suffices for declaration and what some may view as a formal Congressional "Declaration of War" was not required by the Constitution.
Powers of the United States Congress The Constitution also gives Congress an important role in national defense, including the exclusive power to declare war, to raise and maintain the armed forces, and to make rules for the military.[4] Some critics charge that the executive branch has usurped Congress's Constitutionally-defined task of declaring war.[5] While historically presidents initiated the process for going to war, they asked for and received formal war declarations from Congress for the War of 1812, the Mexican–American War, the Spanish–American War, World War I, and World War II,[6] although President Theodore Roosevelt's military move into Panama in 1903 did not get Congressional assent.[6] Presidents have initiated war without Congressional war declarations; Truman called the Korean War a "police action"[7] and the Vietnam War lasted over a decade without a declaration of war.[6] In 1970, Time magazine noted: "All told, it has been calculated, U.S. presidents have ordered troops into position or action without a formal congressional declaration a total of 149 times" before 1970.[6] In 1993, one writer noted "Congress's war power has become the most flagrantly disregarded provision in the Constitution," and that the "real erosion (of Congressional authority to declare war) began after World War II."[8] President George H. W. Bush claimed he could begin Operation Desert Storm and launch a "deliberate, unhurried, post–Cold War decision to start a war" without Congressional approval.[8] Critics charge that President George W. Bush largely initiated the Iraq War with little debate in Congress or consultation with Congress, despite a Congressional vote on military force authorization.[9][10] Disagreement about the extent of congressional versus presidential power regarding war has been present periodically throughout the nation's history.[11]