US President Barack Obama delivers a prime time address from the Cross Hall of the White House, in Washington, DC, USA, 10 September 2014. (Saul Loeb / Pool/EPA)

President Obama had better take care in his consultations with Congress on plans to combat the Islamic State. Secretary of State John Kerry may be able to assemble a durable coalition of overseas partners to join with U.S. forces. But any congressional buy-in to Obama’s strategy is likely to come in the form of a short-term loan that will get called if the going gets rough.

In tackling the Islamic State, Congress is confronted with two incompatible goals: eliminating the terror group as a threat to U.S. national security and avoiding another major military commitment in the Middle East. Satisfying those opposing imperatives will be Congress’s preoccupation.

The likely stratagem for responding to Obama? A legislative maneuver honed over years: Have it both ways.

Recall when Obama announced in the Rose Garden in August 2013 that military strikes were the right thing to do in response to Syria’s use of chemical weapons?

Obama was responding, in part, to congressional hawks such as Sen. John McCain who demanded action in the face of Syrian dictator Bashar al-Assad’s carnage against his own people. The president’s reluctance to enter the Syrian morass had been loudly denounced on Capitol Hill. Calls for intervention and humanitarian action rained down on the White House.

That is, until members of Congress started hearing opposing opinions back home. After all the saber-rattling, Congress refused to go on record supporting the strikes.

Then, after lawmakers bugged out on Obama, Syria renounced the use of chemical weapons and arranged to get rid of the stockpile under an agreement brokered by the United States and Russia — which never would have happened without the threat of strikes. Congress ended up having its cake and eating it, too.

There was a similar contour in the Iraq story.

In 2002, teeth-gnashing reigned supreme on Capitol Hill over the tyrant Saddam Hussein and the threat his regime posed to the region. Lawmakers, convinced that something had to be done, put their votes where their mouths were and authorized the use of force against Iraq. The measure handily passed the House and Senate.

After a widely applauded and expertly launched U.S. invasion, however, sectarian warfare broke out, nearly breaking the country apart. Body bags began coming home. A great many in Congress switched sides, and the enemy became George W. Bush.

Lawmakers blamed Bush for convincing them that Hussein had weapons of mass destruction, an administration claim that turned out to be false. But don’t be fooled. If post-Saddam Iraq had bloomed as a strife-free democracy bestowing liberty and justice on all — and with little cost to the United States — Congress, notwithstanding the WMD myth, would have boasted and chest-thumped to a fare thee well.

Obama should have learned by now that, when it comes to dicey military action in our never-ending political season, Congress will always seek to gain the advantage by having it both ways.

Waiting for Congress to put up or shut up on proposed military involvement against the Islamic State is tantamount to waiting for darkness to go away. The best Obama will get out of the House and Senate may be a green light to train and equip moderate Syrian forces and conduct airstrikes on Islamic State targets. The administration will still be criticized for not going far enough or acting soon enough, though the critics won’t spell out what that means.

Congress at all times reserves the right to point with pride when things go well and to cast blame and flee at the first sign of trouble.

Now, in fairness, there is a firm basis for some of the congressional wariness about war authorizations. The Iraq war resolutions allowed the Bush administration to take the country to a degree of involvement many Americans never expected or wanted.

In addition to the Iraq experience, there is a more searing reason to approach war resolutions with care: the 1964 Gulf of Tonkin resolution. Most members of Congress thought they were granting authority for limited, short-term military strikes in response to alleged actions by North Vietnam against U.S. forces . The Johnson administration, however, regarded the resolution as giving the president a free hand to launch a full-scale war that ended up costing thousands of lives and an American fortune. But that history doesn’t excuse Congress from doing its constitutional duty.

All this is to say, President Obama needs to continue his strong resolve to deal with the Islamic State. Hear all the facts, listen to the opinions, consult and collaborate with Congress. But ultimately, Obama, keeping the country’s best interest foremost, must follow his own mind.

Because if he follows Congress, he’ll just end up eating its dust.

Read more from Colbert King’s archive.