The Perils of Piecemeal Intervention in Syria SYRIA'S rebels are in retreat, President Bashar al-Assad's loyalist forces are laying waste to their former strongholds, and the death toll is mounting: the latest United Nations reports put it around 7,500. As the body count has increased, so, too, have calls for outside intervention. It's time for the West to step in - but only after honestly debating what it will take to stop the carnage. Policy makers and advocacy groups have spent the past few weeks scrambling to come up with solutions. So far most of the discussion has focused on half-measures: arming the rebels or setting up opposition safe havens on Syria's borders. Proponents of these policies argue that they will stop the bloodshed while allowing the United States and its allies to avoid another full-scale intervention so soon after Libya. The impulse to find a way to end the violence is understandable - indeed, I share it. But the debate over intervention to date has played up the benefits of piecemeal options while understating their dangers. Partial measures may seem attractive, but they risk turning a small local conflict into a far messier regional war. Strange as it sounds, doing something small may be worse than doing nothing - meaning the West should go in big or stay home. Arming the rebels sounds easy and intuitive. After all, this is Syria's war; why not let the Syrians fight it out? Mr. Assad has the opposition outgunned, but maybe if the rebels get better weapons they could turn the tide. According to news reports, Saudi Arabia, Qatar and even Al Qaeda aren't waiting for permission: they're already funneling weapons to Sunni opposition groups. Why shouldn't Washington do likewise? The problem is that merely arming the rebels is unlikely to end the conflict, and could well fuel the fire. The opposition we'd be aiding is fragmented and disorganized. And our understanding of its composition and ideology is largely based on guesswork. What we do know is that Syria is a deeply divided country, with a minority-based government presiding over mutually hostile religious groups (Sunnis, Alawites, Christians, Druse) and ethnicities (Arabs, Kurds). Add more gunpowder to the mix and you have a recipe for an ugly intercommunal war. Such a conflict would dwarf the turmoil seen so far, send refugees flooding across Syria's borders and draw in outside powers. Creating safe havens for fleeing civilians might sound like a better idea, since these would be more clearly defensive. But in practice they could prove just as problematic. Without major outside support, such sanctuaries would risk being overrun by hostile forces, as they were in Bosnia in 1995. And with full protection, they could become bases of operations for rebels fighting outside the safe zones, again expanding the war. Neither of these options, moreover, would address the central question: Who should rule Syria and how? The only sure way to quickly stop the killing and replace the Assad regime with something better would be to do what few have been willing to advocate so far: start a serious military operation to topple the government. This would mean a Libya-style coalition air campaign but shouldn't require many boots on the ground. Western air power could make short work of Mr. Assad's army: though often described as formidable, the Syrian military is having trouble completely suppressing the rebels and could never withstand a sustained outside onslaught. After all, Saddam Hussein's much feared and much bigger army dissolved quickly in the face of American firepower. Nor would intervening worsen the West's confrontation with Iran, Syria's one close ally. It's inconceivable that Tehran, which is totally preoccupied with its own defense, would lend substantial military muscle to Syria's government. Nor would Iran's proxies, Hezbollah and Hamas, be likely to intervene. Both are populist movements whose supporters have far more sympathy for the Syrian rebels than the government. Hamas has already closed its Damascus office and denounced Mr. Assad. Hezbollah has been quieter and has refused to abandon its Syrian patrons, but it is ultimately most concerned with protecting its power and position in Lebanon. It is not likely to pick any fights that jeopardize that. An air war next door also wouldn't be likely to affect Iran's nuclear calculus. If Tehran ultimately returns to the bargaining table, it will be because intense Western pressure has convinced the mullahs they have no other option. Still more pressure won't reverse this, for the simple reason that Iran's leaders are already about as paranoid and isolated as they could possibly get. This doesn't mean intervention in Syria will be easy: any campaign will be violent and expensive, and unless it's handled right - by drawing in regional allies and securing full cooperation from rebel forces - the aftermath could be long and messy. A multilateral process for devising a stable, representative, post-Assad government will take time. The Obama administration does not want to hear any of this. It just got out of Iraq and is trying to get out of Afghanistan and stay out of Iran; it has little stomach for yet another war in yet another Muslim country. But let's not pretend that half-measures are preferable. Choosing policies just because they are cheap, gratifying and politically palatable is rarely a good idea, especially when they could well make matters worse. Those of us unwilling to tolerate more slaughter in Syria must confront the true nature of the military choices facing us. We must now accept the hard facts and make an honest decision about what standing up for our interests and values will entail. If that means a major armed intervention, we should do it, but with no illusions.