The White House's proposed strikes on Syria almost couldn't be more limited. They're likely to cost in the millions of dollars rather than the billions of dollars, and no U.S. lives are likely to be in danger. It's "barely five percent of what we did in Libya," says Rep. Brad Sherman.

And it's not just the White House. The congressional authorization of force — if one ever passes — will expressly forbid committing ground troops. So even if the Obama administration wanted to escalate sharply, they'd need to persuade a reluctant Congress to pass a new law allowing them to do so.

So why is there so much debate over such a seemingly costless endeavor? Because things might go wrong. In particular, these 10 things could go wrong:

1) Our strikes could result in heavy civilian casualties. It would be the bitterest of ironies if we struck Syria to punish Assad's barbarism only to end up killing thousands of innocent civilians ourselves. The Pentagon is working up a target list with the express intent of limiting Syrian casualties. But the intelligence behind that list could be wrong — remember when we bombed the pharmaceutical plant in Sudan, or the Chinese embassy in Belgrade? — and we could hit a building full of civilians. Or a missile could malfunction. Or Assad could move civilians into the way of our strikes expressly to secure a propaganda coup.

2) Our strikes could result in Assad killing more civilians. Secretary of State John Kerry was clear before the Senate that he expects our strikes to weaken Assad's position in the civil war. David Ignatius interviewed a rebel leader who said that the strikes "could change the balance of the civil war in Syria."

We know that civilian casualties rise when civil wars turn against the regime. So if Assad feels more threatened after the strikes, and his forces begin massacring more innocents in an attempt to break the will of the opposition, what will we do then? Stand by, as long as they use conventional weapons? This is how escalation happens.

3) Our strikes could result in Assad killing more civilians with chemical weapons. If the regime is truly desperate and Assad (correctly) believes that the torturous congressional debate and low public support signal a limited appetite for engaging in Syria, Assad might respond to the bombs by doubling down on the attacks. The thinking here could be to telegraph defiance of the United States to his supporters and implacable, unstoppable ruthlessness to the opposition. Is it likely? Probably not. But it could happen. And then what will we do? The arguments being made before Congress certainly suggest that having committed ourselves to defending the ban on chemical weapons once, we have to keep defending it.

4) The attacks are so slight that Assad survives them easily and appears strengthened before the world. Sen. James Risch worried about this Tuesday. What "if we go in with a limited strike and, the day after or the week after or the month after, Assad crawls out of his rat hole and says, 'Look, I stood up to the strongest power on the face of this Earth and I won?' " He asked.

Kerry replied that "Assad may be able to crawl out of the hole and say, look, I survived, but there's no way that with reality and other assessments he's going to be able to say he's better off." But perhaps reality and independent assessments don't matter as much as the perception inside Syria. And predicting perceptions of the aftermath of airstrikes that haven't happened yet is difficult at best.

5) "You bombed it, you own it." The "Pottery Barn Rule" —- "you break it, you buy it" — became famous during the Iraq war. "You are going to be the proud owner of 25 million people," Colin Powell told President Bush before the invasion of Iraq. "You will own all their hopes, aspirations and problems. You'll own it all." (As it happens, that's not the Pottery Barn's rule. They simply write off broken merchandise as a loss.)

Syria isn't Iraq. But a congressional force authorization followed by a bombing campaign will firmly involve us in Syria. It will make it much harder for us to say that what happens in Syria isn't our problem. It will mean many more members of the Syrian opposition have contacts with Washington journalists and defense policymakers. The Obama administration believes it can send some missiles and be done with it. That may not prove true.

6) Reprisal. The Syrian army, Syrian army sympathizers, Syrian army allies like Hezbollah, or some other pro-Syrian — or at least anti-American — element could decide to exact revenge for our strikes in Syria by launching a terrorist attack against Americans somewhere else in the world. If 12 American tourists die after a Syria-related terrorist attack on an international hotel in the Middle East, what happens next? Do we mourn? Escalate? Is that a cost we're willing to pay?

7) Assad falls and the chemical weapons end up in the wrong hands. Maybe our strikes do tip the balance against Assad, either by directly degrading his military strength or by emboldening the opposition. What happens to his chemical weapons then? The opposition almost certainly doesn't know where they are. But Assad's top loyalists do. And they'll need to make some money fast ...

8) Assad falls and is replaced by chaos. One reason the United States has been so careful to plan a limited strike is that though Assad is a monster, we're not sure that he'll be replaced by anyone better. Maybe our strikes unexpectedly tip the balance against Assad, but what comes next is chaotic jockeying between moderate and jihadist elements of the opposition, with a dose of revenge killings for good measure.

9) Assad falls and is replaced by something worse. Maybe our strikes unexpectedly tip the balance against Assad and the Al Nusra Front, which claims allegiance to al Qaeda, wins the resulting power struggle, or has a major role in the coalition. At Tuesday's hearings, Kerry said he believes that unlikely. He said that recent data show that the number of "extremists" in the opposition is "lower than former expectations." He also argued that "Syria historically has been secular, and the vast majority of Syrians, I believe, want to remain secular."

But what if he's wrong? The United States has officially designated Al Nusra a terrorist organization. Are we really going to be complicit in permitting them, or anyone like them, to take over Syria?

10) Escalation. Almost everything that could go wrong points towards the same ultimate response: Escalation. That could mean more bombing, or actual ground troops, or some combination. But the key fear behind intervening in Syria is that even constrained missions can unexpectedly break free of their limits.

That's why Kerry's early equivocation over whether the authorization of force should expressly forbid ground troops so scared the Senate, and the White House. He quickly walked it back, but it's worth taking his original comments seriously:

In the event Syria imploded, for instance, or in the event there was a threat of a chemical weapons cache falling into the hands of al-Nusra or someone else and it was clearly in the interest of our allies and all of us, the British, the French and others, to prevent those weapons of mass destruction falling into the hands of the worst elements, I don't want to take off the table an option that might or might not be available to a president of the United States to secure our country.

This is what we call a "Kinsley gaffe": Kerry was accidentally telling the truth. If we're involved in Syria and something goes wrong, ground troops might make sense. Escalation might make sense. And that's a major reason so many people are afraid of intervening in the first place.

One caution here is that much of what could go wrong if we intervene could go wrong if we don't intervene, too. But that's where the Pottery Barn rule comes in. Once we're involved, it's a lot harder to say that disastrous outcomes in Syria are simply an awful, regrettable thing happening elsewhere in the world rather than a war we are directly involved in, and that we have some responsibility in guiding toward a successful conclusion.

The fact that things could go wrong in Syria doesn't mean it's not worth intervening. As Max Fisher points out, there's a real argument to be made for enforcing the ban on chemical weapons. But the upsides need to be balanced against a realistic view of the risks in any intervention.