Forget what we learned in civics.

Our leaders don’t read or heed the Constitution.

Article I, Section 8, clearly states Congress has sole power “to declare war,” yet that’s what we did earlier this month by instituting a no-fly zone in Libya.

But wait, it gets better.

We did this on the eighth anniversary of invading Iraq.

As if two wars, in Iraq and Afghanistan, didn’t bleed us dry, now we’ve waded into territory controlled by the tyrant of Tripoli. How this is supposed to end remains murky.

After more than 40 years in power and four Time magazine cover stories going back to when President Reagan referred to the daffy-dressing dictator as the “mad dog of the Middle East,” we can’t even agree on how to spell Muammar Gaddafi.

It’s been more than 60 years since Harry Truman in 1950 steered clear of Capitol Hill and sent U.S. troops to Korea without a war declaration.

Commanders in Chief on both sides of the political divide, including President Obama, can agree on that.

Consult Congress, perhaps, but initiate military action.

“The president does not have the power under the Constitution to unilaterally authorize a military attack in a situation that does not involve stopping an actual or imminent threat to the nation,” candidate Obama told The Boston Globe in 2007 in his presidential campaign.

“History has shown us time and again … that military action is most successful when it is authorized and supported by the legislative branch.”

This one seems particularly to possess limited U.S. interests, even when it comes to oil.

Obama, who by turns is characterized as a wild lefty and too timid, made no one happy.

For hawks who wanted us there a month ago, he came off as dithering and too cautious.

For war-weary doves wary of yet another open-ended commitment in the Muslim world, Obama’s restraint resolved into recklessness.

What really made Republicans’ heads twirl around on their shoulders, however, is that the United States held out for a supporting role while the French took the reins.

“We have a Spectator in Chief,” fumed Newt Gingrich.

Sen. Lindsey Graham faulted Obama for acting as if “leading the free world is an inconvenience.” It’s a clear departure from Cold War diplomacy, where we cracked the whip to cajole other countries into collective action.

That lead role wasn’t very satisfying, either, with America paying all prices and bearing all burdens.

Recall that’s kind of how we got to Baghdad. Impatient President George W. Bush recoiled at giving international inspectors more time on those weapons of mass destruction.

We charged into that conflict without any Muslim allies.

With every nation-rebuilding setback in Iraq, we grew more isolated and identified as an Arab enemy. Iraq was a departure from our usual role, reluctant imperial power lacking expansionist impulses.

We stayed out of World War I for three years. We avoided World War II until Japan attacked Pearl Harbor and Hitler continued his quest for world domination.

Most of our problems in my lifetime, like Vietnam, ensued from plunging into places on the other side of the globe in the name of preventing communist takeovers.

March 12 the Arab League formally requested that the United Nations impose the no-fly zone — a first in 66 years against one of its members because of human-rights violations.

Five days later, when the U.N. Security Council passed resolutions authorizing action against Gaddafi’s forces, France and Britain were ready to go.

U.N. Ambassador Susan Rice, 46, made a case for humanitarian action.

She was on the staff at the National Security Council in 1994 when the world stood idly by during genocide in Rwanda.

“I swore to myself that if I ever faced such a crisis again, I would come down on the side of dramatic action, going down in flames if that was required.”

Obama has repeatedly referred to regime change in Libya as a goal, but the air strikes are meant to prevent Gaddafi from slaughtering his own people.

What if rebels can’t dislodge him, he clings to power and won’t leave, Libya becomes partitioned with Tripoli controlled by Gaddafi and Benghazi held by the opposition and Col. Crazy becomes another Osama bin Laden to smoke out?

We must at least guard against the tendency to escalate military missions, following examples pioneered by Gen. Dwight Eisenhower, John Kennedy with the Bay of Pigs and Reagan in Lebanon.

In transferring command and control to NATO, the U.S. is turning the reins over to an organization dominated by the U.S., militarily and politically.

The United States supplies 22 percent of NATO’s budget, almost as much as the next largest contributors — Britain and France — combined.

I liked how The Associated Press put it: “In essence, the U.S. runs the show that is taking over running the show.”

Despite insistences that the operation is only to protect civilians, airstrikes are undeniably helping rebels advance.

Defense Secretary Robert Gates said March 27 that the crisis in Libya “was not a vital national interest to the United States, but it was an interest.”

“Some nations may be able to turn a blind eye to atrocities in other countries,” Obama said.

“The United States of America is different. And as president, I refused to wait for the images of slaughter and mass graves before taking action.”

Here’s where the slope gets slipperier because folks are also fleeing Ivory Coast to escape its despot.

Presidents pick and choose their fights according to the crisis and circumstances at hand, not by any doctrine about how to rationalize using force in one locale, but not another.

Obama certainly is well aware of that if he read his own book, “The Audacity of Hope,” where he wrote the U.S. risks lacking international legitimacy if it intervenes militarily “without a well-articulated strategy that the public supports and the world understands. Why invade Iraq and not North Korea or Burma? Why intervene in Bosnia and not Darfur?”

Why, indeed?

John Eby is managing editor of the Daily News. E-mail him at john.eby@leaderpub.com.