Syria is trapped on a crumbling precipice, and however it might fall will entail significant risks for the United States and for the Syrian people.

The brutal regime of Bashar al-Assad is employing its loyal military forces and sectarian thugs to crush the opposition and reassert its tyranny. Even if Bashar fails, Syria may not be out of the woods: an increasingly likely alternative to the current regime is a bloody civil war similar to what we saw in Lebanon, Bosnia, Congo, and most recently in Iraq. The horrors of such a war might even exceed the brutal reassertion of Assad’s control, and would cause spillover into Syria’s neighbors—Turkey, Iraq, Jordan, Lebanon, and Israel—that could be disastrous for them and for American interests in the Middle East.

But the unrest in Syria, which is now entering its second year, also offers some important opportunities, ones that would come from the fall of the regime of Bashar al-Assad, whose family has ruled the country with an iron grip for over forty years. Syria is Iran’s oldest and most important ally in the Arab world, and the Iranian regime has doubled down on Assad, providing him with financial aid and military support to shore up his regime. Assad’s departure would deal a significant blow to Tehran, further isolating it at a time when it has few friends in the region or the world. In addition, Damascus is steadfast in its hostility toward Israel, and Assad’s regime is also a longtime supporter of terrorist groups like Hezbollah and Hamas, and has at times aided al-Qa’ida terrorists and former regime elements in Iraq. The regime’s collapse, therefore, could have significant benefits for the United States and its allies in the region.

Actually ousting Assad, however, will not be easy. Although the Obama administration has for months called for Assad to go, every policy option to remove him is flawed, and some could even make the situation worse—seemingly a recipe for inaction. Doing nothing, however, means standing by while Assad murders his own people, and Syria plunges into civil war and risks becoming a failed state. Already the violence is staggering: as of March 2012, at least 8,000 Syrians have died and thousands more have been arrested and tortured in trying to topple the regime. At the same time, Syria is fragmenting. The Syrian opposition remains divided, and the Free Syrian Army is more a brand than a meaningful, unified force. Al-Qa’ida is urging fighters to join the fray in Syria, and sectarian killings and atrocities are growing. Should the violence continue to intensify, Syria’s neighbors may increase their meddling, and instability could spread, further weakening already-fragile neighbors like Iraq and Lebanon.

So to protect U.S. interests, Assad cannot triumph. But a failed Syria, one wracked by civil war, would be just as bad. Thus, U.S. policy must walk this tightrope, trying to remove Assad, but doing so in a way that keeps Syria an intact state capable of policing its borders and ensuring order at home. At the end of the day, however, removing Assad may not be doable at a price the United States is willing to pay. If so, the U.S. government may be forced to choose between living with a brutal but weakened Assad or getting rid of Assad regardless of the consequences.

This memo lays out six options for the United States to consider to achieve Assad’s overthrow, should it choose to do so:

  1. Removing the regime via diplomacy;
  2. Coercing the regime via sanctions and diplomatic isolation;
  3. Arming the Syrian opposition to overthrow the regime;
  4. Engaging in a Libya-like air campaign to help an opposition army gain victory;
  5. Invading Syria with U.S.-led forces and toppling the regime directly; and
  6. Participating in a multilateral, NATO-led effort to oust Assad and rebuild Syria.

The options are complex, and policymakers will probably try to combine several in an attempt to accentuate the positives and minimize the negatives, which will inevitably be difficult and bring out new complications. But by focusing on discrete approaches, this memo helps expose their relative strengths and weaknesses. For each course of action, this memo describes the strategy inherent to the option and what it would entail in practice. It also assesses the option’s advantages and disadvantages.

This memo does not endorse any particular policy option. Rather, it seeks to explain the risks and benefits of possible courses of action at this moment in time. As conditions change, some options may become more practical or desirable and others less so. The authors mostly agree on the advantages and disadvantages of each approach but weigh the relative rewards and costs differently.

By Daniel L. Byman, Michael Doran, Kenneth M. Pollack and Salman Shaikh