The recent massacre by the Syrian government of 108 people, mostly women and children, will inevitably put intense pressure on a reluctant Obama administration to take out President Bashar al-Assad using force. As was obvious when the United States evicted Libya’s Moammar Gadhafi after he threatened to kill lots of his compatriots, hawks thirsting for future American intervention in the world will use this as a bloodless (that is, free of American blood) model to depose dictators from the air. But the administration, which also has been rash in its expansion of the drone war against al-Qaeda and related groups, has wisely avoided intervention in Syria for a variety of good reasons.

The main reason is that military action in Syria would not be as easy as it was in Libya. And the use of armed force in Libya seems easier in retrospect than it was—it dragged out for months with no conclusion, with some bitten nails on the part of the administration.

Ever since Bill Clinton learned in Somalia in 1993 that inserting substantial U.S. ground forces into developing countries could backfire or lead to a quagmire, the American model has been to find a local force to hold an enemy in position on the ground while using U.S. air power to pummel opposing forces. The model was used successfully in Bosnia and Kosovo in the mid- to late-1990s, to initially take out the Taliban in 2001, and to depose Gadhafi in Libya in 2011. By the time of the Iraq invasion in 2003, the model had worked so well that Secretary of Defense Donald Rumsfeld decided that air power was now so dominant in warfare that smaller American ground forces could support U.S. air power against even more formidable military opponents, such Saddam Hussein’s Iraqi forces. Previously, since the invention of the airplane, aircraft had supported ground forces or bombed independently of them.

Rumsfeld was probably correct that smaller ground forces, U.S. or local, can support massive U.S. air power against more capable adversaries (as Iraq has shown, however, occupying the country or fighting guerrillas will require many more ground forces). Furthermore, dictators sometimes can be eliminated without U.S. forces on the ground, as long as local forces are capable. The problem in Syria is that the opposition is less capable and more splintered and chaotic than in Libya, and the Syrian military is much stronger. In Libya, Gadhafi deliberately kept his military weak so that it wouldn’t threaten his power. Assad—with the militarily capable Iraq, Turkey, and Israel on his borders—hasn’t had that luxury and therefore has maintained fairly capable armed forces with much better air defenses than Libya possessed.

So if American air power failed to take out Assad, which would be a real possibility, pressure could mount quickly to insert U.S. ground forces. This outcome would be risky and potentially disastrous in an election year. That is why Obama has been reluctant to escalate the Syrian situation.

What happens after the election is another story. If Obama wins, he won’t face re-election and may be less cautious about trying to remove Assad from power. Mitt Romney—who tries to be all things to all people, and like George W. Bush when he entered office, doesn’t seem to have a coherent worldview—could be easily persuaded by his many neoconservative foreign policy advisers to go after Assad. Romney has already called for arming the opposition. So whichever candidate wins, disaster could ensue in Syria.

If U.S. ground forces were used, a repeat of Iraq could occur: a protracted guerrilla insurgency plus a civil war among a population with similar ethno-sectarian fractures—with al-Qaeda as one of the participants. Libya still has the possibility of a civil war breaking out among tribal militias armed to the teeth, but Syria has even more volatile political fissures.

Arming the opposition can also lead to the slippery slope of U.S. military intervention. Even the currently cautious Obama administration is providing “non-lethal” aid to the Syrian opposition and looking the other way as Sunni Arab Gulf states provide weapons. Yet non-lethal aid is a misnomer, because although it may not shoot, much of it, such as communication devices, dramatically improves the combat power of the Syrian opposition, thus escalating the killing.

Although it is difficult for Americans to watch Assad kill his own people, what comes after Assad might be even worse for the region and the United States. The United States should stay on the sidelines and let regional powers, such as Turkey and Saudi Arabia, take the lead in dealing with the Syrian mess. The United States can no longer afford to be the world’s policeman—either morally or financially.