By George Friedman

Images of multiple dead bodies emerged from Syria last week. It was asserted that poison gas killed the victims, who according to some numbered in the hundreds. Others claimed the photos were faked while others said the rebels were at fault. The dominant view, however, maintains that the al Assad regime carried out the attack.

The United States has so far avoided involvement in Syria's civil war. This is not to say Washington has any love for the al Assad regime. Damascus' close ties to Iran and Russia give the United States reason to be hostile toward Syria, and Washington participated in the campaign to force Syrian troops out of Lebanon. Still, the United States has learned to be concerned not just with unfriendly regimes, but also with what could follow such regimes. Afghanistan, Iraq and Libya have driven home the principle that deposing one regime means living with an imperfect successor. In those cases, changing the regime wound up rapidly entangling the United States in civil wars, the outcomes of which have not been worth the price. In the case of Syria, the insurgents are Sunni Muslims whose best-organized factions have ties to al Qaeda.

Still, as frequently happens, many in the United States and Europe are appalled at the horrors of the civil war, some of whom have called on the United States to do something. The United States has been reluctant to heed these calls. As mentioned, Washington does not have a direct interest in the outcome, since all possible outcomes are bad from its perspective. Moreover, the people who are most emphatic that something be done to stop the killings will be the first to condemn the United States when its starts killing people to stop the killings. People would die in any such intervention, since there are simply no clean ways to end a civil war.

Obama's Red Lines

U.S. President Barack Obama therefore adopted an extremely cautious strategy. He said that the United States would not get directly involved in Syria unless the al Assad regime used chemical weapons, stating with a high degree of confidence that he would not have to intervene. After all, Syrian President Bashar al Assad has now survived two years of civil war, and he is far from defeated. The one thing that could defeat him is foreign intervention, particularly by the United States. It was therefore assumed he wouldn't do the one thing Obama said would trigger U.S. action.

Al Assad is a ruthless man: He would not hesitate to use chemical weapons if he had to. He is also a very rational man: He would use chemical weapons only if that were his sole option. At the moment, it is difficult to see what desperate situation would have caused him to use chemical weapons and risk the worst. His opponents are equally ruthless, and we can imagine them using chemical weapons to force the United States to intervene and depose al Assad. But their ability to access chemical weapons is unclear, and if found out, the maneuver could cost them all Western support. It is possible that lower-ranking officers in al Assad's military used chemical weapons without his knowledge and perhaps against his wishes. It is possible that the casualties were far less than claimed. And it is possible that some of the pictures were faked.

All of these things are possible, but we simply don't know which is true. More important is that major governments, including the British and French, are claiming knowledge that al Assad carried out the attack. U.S. Secretary of State John Kerry made a speech Aug. 26 clearly building the case for a military response, and referring to the regime attack as "undeniable" and the U.S. assessment so far as "grounded in facts." Al Assad meanwhile has agreed to allow U.N. inspectors to examine the evidence onsite. In the end, those who oppose al Assad will claim his supporters concealed his guilt, and the insurgents will say the same thing if they are blamed or if the inspectors determine there is no conclusive evidence of attacks.

The truth here has been politicized, and whoever claims to have found the truth, whatever it actually is, will be charged with lying. Nevertheless, the dominant emerging story is that al Assad carried out the attack, killing hundreds of men, women and children and crossing the red line Obama set with impunity. The U.S. president is backed into a corner.

The United States has chosen to take the matter to the United Nations. Obama will make an effort to show he is acting with U.N. support. But he knows he won't get U.N. support. The Russians, allies of al Assad and opponents of U.N.-based military interventions, will veto any proposed intervention. The Chinese — who are not close to al Assad, but also oppose the U.N.-sanctioned interventions — will probably join them. Regardless of whether the charges against al Assad are true, the Russians will dispute them and veto any action. Going to the United Nations therefore only buys time. Interestingly, the United States declared on Sunday that it is too late for Syria to authorize inspections. Dismissing that possibility makes the United States look tough, and actually creates a situation where it has to be tough.

Consequences in Syria and Beyond

This is no longer simply about Syria. The United States has stated a condition that commits it to an intervention. If it does not act when there is a clear violation of the condition, Obama increases the chance of war with other countries like North Korea and Iran. One of the tools the United States can use to shape the behavior of countries like these without going to war is stating conditions that will cause intervention, allowing the other side to avoid crossing the line. If these countries come to believe that the United States is actually bluffing, then the possibility of miscalculation soars. Washington could issue a red line whose violation it could not tolerate, like a North Korean nuclear-armed missile, but the other side could decide this was just another Syria and cross that line. Washington would have to attack, an attack that might not have been necessary had it not had its Syria bluff called.

There are also the Russian and Iranian questions. Both have invested a great deal in supporting al Assad. They might both retaliate were someone to attack the Syrian regime. There are already rumors in Beirut that Iran has told Hezbollah to begin taking Americans hostage if the United States attacks Syria. Russia meanwhile has shown in the Snowden affair what Obama clearly regards as a hostile intent. If he strikes, he thus must prepare for Russian counters. If he doesn't strike, he must assume the Russians and Iranians will read this as weakness.

Syria was not an issue that affected the U.S. national interest until Obama declared a red line. It escalated in importance at that point not because Syria is critical to the United States, but because the credibility of its stated limits are of vital importance. Obama's problem is that the majority of the American people oppose military intervention, Congress is not fully behind an intervention and those now rooting the United States on are not bearing the bulk of the military burden — nor will they bear the criticism that will follow the inevitable civilian casualties, accidents and misdeeds that are part of war regardless of the purity of the intent.

The question therefore becomes what the United States and the new coalition of the willing will do if the red line has been crossed. The fantasy is that a series of airstrikes, destroying only chemical weapons, will be so perfectly executed that no one will be killed except those who deserve to die. But it is hard to distinguish a man's soul from 10,000 feet. There will be deaths, and the United States will be blamed for them.

The military dimension is hard to define because the mission is unclear. Logically, the goal should be the destruction of the chemical weapons and their deployment systems. This is reasonable, but the problem is determining the locations where all of the chemicals are stored. I would assume that most are underground, which poses a huge intelligence problem. If we assume that perfect intelligence is available and that decision-makers trust this intelligence, hitting buried targets is quite difficult. There is talk of a clean cruise missile strike. But it is not clear whether these carry enough explosives to penetrate even minimally hardened targets. Aircraft carry more substantial munitions, and it is possible for strategic bombers to stand off and strike the targets.

Even so, battle damage assessments are hard. How do you know that you have destroyed the chemicals — that they were actually there and you destroyed the facility containing them? Moreover, there are lots of facilities and many will be close to civilian targets and many munitions will go astray. The attacks could prove deadlier than the chemicals did. And finally, attacking means al Assad loses all incentive to hold back on using chemical weapons. If he is paying the price of using them, he may as well use them. The gloves will come off on both sides as al Assad seeks to use his chemical weapons before they are destroyed.

A war on chemical weapons has a built-in insanity to it. The problem is not chemical weapons, which probably can't be eradicated from the air. The problem under the definition of this war would be the existence of a regime that uses chemical weapons. It is hard to imagine how an attack on chemical weapons can avoid an attack on the regime — and regimes are not destroyed from the air. Doing so requires troops. Moreover, regimes that are destroyed must be replaced, and one cannot assume that the regime that succeeds al Assad will be grateful to those who deposed him. One must only recall the Shia in Iraq who celebrated Saddam's fall and then armed to fight the Americans.

Arming the insurgents would keep an air campaign off the table, and so appears to be lower risk. The problem is that Obama has already said he would arm the rebels, so announcing this as his response would still allow al Assad to avoid the consequences of crossing the red line. Arming the rebels also increases the chances of empowering the jihadists in Syria.

When Obama proclaimed his red line on Syria and chemical weapons, he assumed the issue would not come up. He made a gesture to those in his administration who believe that the United States has a moral obligation to put an end to brutality. He also made a gesture to those who don't want to go to war again. It was one of those smart moves that can blow up in a president's face when it turns out his assumption was wrong. Whether al Assad did launch the attacks, whether the insurgents did, or whether someone faked them doesn't matter. Unless Obama can get overwhelming, indisputable proof that al Assad did not — and that isn't going to happen — Obama will either have to act on the red line principle or be shown to be one who bluffs. The incredible complexity of intervening in a civil war without becoming bogged down makes the process even more baffling.

Obama now faces the second time in his presidency when war was an option. The first was Libya. The tyrant is now dead, and what followed is not pretty. And Libya was easy compared to Syria. Now, the president must intervene to maintain his credibility. But there is no political support in the United States for intervention. He must take military action, but not one that would cause the United States to appear brutish. He must depose al Assad, but not replace him with his opponents. He never thought al Assad would be so reckless. Despite whether al Assad actually was, the consensus is that he was. That's the hand the president has to play, so it's hard to see how he avoids military action and retains credibility. It is also hard to see how he takes military action without a political revolt against him if it goes wrong, which it usually does.