Here’s a crucial fact that you may not realize, given the week’s headlines: Libya is only a tragic sideshow to the historic events in the Middle East.

Egypt is the place that counts when we consider the prospects for Arab democracy. Bahrain is the locale where Iran and the Saudis are contesting for power. Yemen, whose president is about to fall, is the country where a strong al-Qaida branch is based.

So, it’s essential that Libya not divert scarce U.S. resources from where they are needed. Any protracted involvement will distract our focus from more essential Mideast states that require attention. Yet, given the unplanned way President Obama embarked on this venture, I fear that’s where we are headed.

Unless Obama gets very lucky, we are enmeshed in a new Mideast war.

To understand why, we must revisit how we got mixed up in Libya in the first place. For weeks Obama resisted any military involvement, for good reasons: Libya was not critical to U.S. security or Arab democracy and produces only 2 percent of the world’s oil. And we still have tens of thousands of troops in two Muslim countries.

As Defense Secretary Robert M. Gates bluntly told West Point cadets last month, any U.S. leader who sent American troops into another Mideast war “should have his head examined.”

So who or what changed the president’s mind?

The buzz in Washington gives credit (or blame) to three women. Intervention was pushed by the National Security Council’s human-rights expert, Samantha Power, who studied U.S. failures to stop mass murder in Bosnia and Rwanda, and by U.N. Ambassador Susan Rice, who pushed (unsuccessfully) for U.S. intervention in Darfur. Power and Rice supposedly won over a reluctant Secretary of State Hillary Rodham Clinton just as Moammar Gadhafi’s troops were about to erase the last rebel stronghold in Benghazi.

I, too, believe a looming humanitarian crisis changed Obama’s mind. But there are far worse humanitarian crises where we have avoided any intervention, especially when they involve civil warfare. So why Libya?

My guess is Obama’s about-face was driven by two factors: the CNN/al-Jazeera/Facebook effect, and the over-the-top rhetoric of Libya’s leader.

Much of the Mideast press corps moved en masse from Egypt across the border into Libya after Egyptian President Hosni Mubarak fell. So they were on hand to tell the tragic tales of beleaguered Libyan rebels and to broadcast video images forwarded by trapped civilians.

Then Gadhafi threatened to “show no mercy” to the rebels in Benghazi: This meant he might conduct a civilian slaughter in full view of the entire Arab region and the world ― with Obama standing passively by.

This looming prospect galvanized Obama into an instant decision. It also embarrassed Arab leaders into endorsing an Arab League vote that called for a no-fly zone over Libya. With the Arab League vote in hand, U.S. officials were able to muster a U.N. Security Council vote for a no-fly zone.

But an understandable humanitarian decision is already turning into a trap.

A no-fly zone may save Benghazi, but it can’t get rid of Gadhafi. What looms is a stalemate: U.S. or NATO planes must patrol indefinitely to prevent Gadhafi from going back on the attack.

No-fly zones over Bosnia and Kosovo never removed the Serbian leaders who committed carnage against civilians. Both required more military action. The no-fly zone protecting Iraqi Kurds and Shiites continued for more than a decade, until Saddam Hussein was overthrown on the ground in 2003.

Surely Obama must know this. Yet he seems to be banking on a palace coup to unseat Gadhafi. That could happen, but what if it doesn’t?

Already, some neoconservatives are calling for the United States to send in special forces to train the Libyan rebels, and ensure that the rebels receive better weapons. They make comparisons to Afghanistan: Never mind that the Libyans are inexperienced and ill-trained, unlike the Afghan Northern Alliance, which we helped to overthrow the Taliban.

Neocons are also pushing plans for post-Gadhafi nation-building that sound uncannily familiar. Believe me, trying to do an Iraq redux will not achieve better results.

Neither Obama nor the Pentagon wants to expand U.S. military action. As the chairman of the Joint Chiefs, Adm. Mike Mullen, told NBC, the mission is “narrow in scope” and “focused on humanitarian efforts.” Added Mullen, “The president’s been very clear that we’re not going to put any boots on the ground.”

I hope that’s true. I understand the humanitarian imperative that got our planes flying. And I know the president hopes to hand off those continued flights to our European allies.

But Gadhafi, who has billions in cash stashed in Libya to pay his fighters, has little incentive to go into exile. I find it hard to foresee how this high-minded venture will end.

By Trudy Rubin

Trudy Rubin is a columnist and editorial-board member for the Philadelphia Inquirer. ― Ed.

(The Philadelphia Inquirer)

(McClatchy-Tribune Information Services)