First the President must formally request the Congress for a declaration of war, as under the Constitution the Congress shall have Power: To declare War.
Second Obama without such a declaration of war, like President Jefferson in dealing with the terrorists in The Bay of Tripoli, Obama is limited the military power and resources of America to those of mainly defense in nature.
Third, going back to 1942, before a lot of our time, The Supreme Court, voting 8 to 0, upheld the legality and authorization of trial by tribunal supported by legislation enacted by Congress, i.e. declaration of war.
Fourth, in 2008, The Supreme Court, voting 5 to 4, despite an act of Congress, that attempted to suspend that right o habeas corpus, because the President, Bush at the time, had not asked Congress for a declaration of War.
Fifth, unless Obama seeks a declaration of war, his 2009 Military Commissions Act might also be suspended by the Supreme Court if challenged by one of these enemy combatants, as Congress as not issues a declaration of war against The Taliban, al-Qaeda and al-Qaeda trained fanatical jihadist radical Muslim extremists.
Sixth, while any President could unquestionably adopt such measures as the laws permitted, 2006 or 2009 Military Commissions Act, for the enforcement of order against insurgency, Congress alone could stamp an insurrection with the character of war and thereby authorize the legal consequences ensuing from a state of war. As such without a declaration of war by Congress, Obama can only fight a defensive war against al-Qaeda and al-Qaeda trained fanatical jihadist radical Muslim extremists.
Thus without Obama asking for and Congress granting a declaration of war against our enemy combatants namely, the Taliban, al-Qaeda and al-Qaeda trained fanatical jihadist radical Muslim extremists, in my humble opinion Obama could be considered in violation his oath of office. More preciously “will to the best of my ability, protect, and defend.”
By not asking for a declaration of war against al-Qaeda, the Taliban, and jihadist radical Muslim extremists is Obama doing his best to protect and defend the citizens of America? I believe legally not.
Obama clearly has the ability to ask Congress for a declaration of war, does he not? Thus a legal argument could be made, that he has not upheld his oath of office.