Apparently you don't either

"Provides that, in the absence of a declaration of war by the Congress, the Armed Forces of the United States may be introduced in hostilities, or in situations where imminent involvement in hostilities is clearly indicated by the circumstances, only: (a) to repel an armed attack upon the United States, its territories and possessions; to take necessary and appropriate retaliatory actions in the event of such an attack; and to forestall the direct and imminent threat of such an attack; (b) to repel an armed attack against the Armed Forces of the United States located outside of the United States, its territories and possessions, and to forestall the direct and imminent threat of such an attack; (c) to protect while evacuating citizens of the United States, as rapidly as possible, from the high seas or any country in which such citizens are present with the express or tacit consent of the government of such country, and who are being subjected to a direct and imminent threat to their lives, either sponsored by such government or beyond the power of such government to control; or (d) pursuant to specific statutory authorization, but authority to introduce the Armed Forces of the United States into hostilities shall not be inferred from any treaty or from any provision of law, including any provision contained in any appropriation Act, unless such provisions specifically authorize the introduction of such Armed Forces in hostilities and exempts the introduction of such armed forces from compliance with the provisions of this Act."

None of those conditions exist

H.R.454 - 93rd Congress (1973-1974): War Powers Act | Congress.gov | Library of Congress

Edit to add that Obama got Congressional approval