President Barack Obama stands on the brink of engaging the United States in another war of choice in the Middle East. Ostensibly because the Syrian regime crossed Obama's self-declared "red line" by using chemical weapons, Washington will deliver small arms, including antitank weapons, to Syrian opposition groups favored by the administration. (Obama appears to have overlooked reports by the United Nations that rebel groups may have used the weapons as well.) The administration's red-line bravado became a policy without any deliberation among the American people or their representatives. Consequently, administration officials are now on a propaganda spree trying to justify this blunder, which is likely to have major repercussions for the Middle East, the wider Islamic world, and for U.S. strategic interests. None of this is to discount the horrifying humanitarian disaster unfolding in Syria. The death toll from the fighting has reached 93,000 since the start of the conflict over two years ago. But it's strange to be concerned only about deaths due to chemical weapons when so many thousands more are being killed by more conventional armaments, some of them imported by U.S. allies. The Assad regime appears to have regained the upper hand in the conflict in recent months, in defiance of Obama's repeated statements that Assad must leave. If anything, it is this fact--not the purported use of chemical weapons--that may be driving the administration's decision-making. Obama's red-line policy is only in play now that it appears that Assad's fortunes have improved. The red line serves as convenient justification for U.S. interference. Moreover, the administration (and often the media) reports the death toll as if every Syrian killed were a casualty of the regime. But let's be clear: both sides have needlessly and ruthlessly killed thousands of Syrians, with one recent report estimating that Assad supporters constitute 43 percent of the dead. This is an ethnic and sectarian civil war and neither side is a reliable champion of democracy. This conflict has become in large part a Shia-Sunni conflict with the potential to devastate large swaths of the Middle East. The Syrian rebellion began as an inspiring show of opposition to the corrupt and repressive single-party government that has ruled the country since 1971. But as protesters took up arms in response to the regime's crackdown on demonstrators, the rebellion was hijacked by extremist groups. Among the groups are sectarian militias and terrorist groups like the al-Qaeda-affiliated Jabhat Al-Nusra--the strongest and most organized of the opposition fighters. Supported by the non-democratic Sunni regimes of Saudi Arabia and Qatar with billions of dollars, these groups are taking the lead among the many militias operating in Syria. The Free Syrian army, now led by General Salim Idris, is an offshoot of the army of Bashar al-Assad. It has no democratic credentials but fewer ties to the extremist elements, and so has been more favored by U.S. policymakers. This stew of groups fighting for preeminence among the opposition often clouds another terrible reality: If the opposition wins, it will likely result in a slaughter of Alawites, Christians, and other minorities protected by the Assads during the course of their long regime. Syria's strategic geographic position, along with its alliances with Iran, Russia, and Hezbollah, creates a complicated reality for U.S. and European interests, with U.S. intervention liable to escalate tensions on each of these fronts. Moreover, if the United States enters the civil war in Syria, it will be another Islamic country in which the U.S. has engaged in conflict at a time when many Muslims throughout the world see our foreign policy as chiefly a war on Islam. We have been here before, entering a conflict in which there is no end in sight and no vital U.S. interest at stake. Once more, the war hawks are worried that we are about to lose a proxy war to Iran. They fail to see the obvious: by sinking more resources into the Syrian conflict, we risk weakening our struggling economy and stretching our military resources for no evident purpose. They may have already forgotten that Iran was the chief geopolitical beneficiary of the U.S. war in Iraq. Syria is in a tragic position. The death and carnage is heart-wrenching, and the continued abuse of Syrians by Assad is despicable. But U.S. involvement will only broaden the conflict. We should not get involved in this civil war with unknown and dangerous ramifications for the region and ourselves. We should not get involved in supporting an opposition that is ready to inflict a bloodbath on Syrian minorities, and we should not abet the rise of extremist al-Qaeda-affiliated groups. Finally, we should not fuel the Shia-Sunni conflict by taking sides unless we want a reprise of what happened in Iraq. This time, let's resist the temptation to step into the fight. This time, let's say "lesson learned."