It should go without saying that Congressional authorization is required for an ongoing war against ISIS, but we all understand that this isn’t going to happen. Neither the post-9/11 AUMF nor the authorization for invading Iraq applies to this conflict, as Robert Golan-Vilella makes  very clear, and the president is not entitled to wage war on his own authority. Nonetheless, the president will probably continue to wage war without any authorizing vote from Congress because he can and because he has done so once already in his presidency and suffered no consequences. Among the many other things wrong with the Libyan war, it was illegal under U.S. law, and hardly anyone cared about this. It wouldn’t be surprising if Obama concludes that he can do the same thing in fighting ISIS, which at least has some tenuous connection to American security in a way that bombing Libya never did.
Back in 2011, the administration stood by its dishonest claim that the war in Libya never amounted to “hostilities” and therefore didn’t require Congressional action. This was transparent nonsense, but very few people worried about it. The president’s partisans mostly stayed quiet about the war’s illegality, and Republican hawks were more concerned that the U.S. wasn’t acting aggressively enough and had waited too long to start the bombing. Besides, most of the latter had no principled objection to a president waging war on his own authority, since they already held a very broad view of the executive’s war powers. The U.S. waged a war in Libya for eight months while pretending that it was not doing this, and for all practical purposes Obama got away with it.
He would have and easily could have done the same thing in Syria last summer, but encountered a problem when Parliament refused to rubber-stamp British participation in the intervention. Cameron felt compelled to back out of the impending attack, which made it more difficult for Obama to proceed without seeking a vote in Congress. While insisting that he still didn’t need to go to Congress, Obama chose to do so anyway. That was the right decision, but one that brought him far more grief and political damage than his illegal war in Libya. Since Obama obviously has no scruples about waging an illegal war, the lesson for him from these two episodes was clear: seeking authorization from Congress for military action is the politically risky and unnecessary move, and waging a war without Congressional approval is the safer bet. That’s how warped our foreign policy debate and political culture have become.
If Obama doesn’t go to Congress to get authorization for the ever-expanding mission against ISIS, he will be violating U.S. law again, but the depressing truth is that even fewer people will care this time. Many Democrats in Congress are embarrassed and annoyed  by Sen. Kaine’s efforts to bring the matter to a vote before the midterms, since they would rather avoid having to take a potentially controversial position so close to an election. Most Republicans in Congress see no need for a vote in the first place. One of the biggest problems that Republican hawks had with Obama during last year’s Syria debate was that he went to Congress at all, and they would probably be even more outraged if he did so again. Once again, the U.S. will wage an illegal war without any meaningful dissent from the members of Congress that have the sole constitutional responsibility for authorizing when the U.S. goes to war.