Another political virtue is the impact intervention would have on Iran. Ousting Tehran’s last reliable satellite regime and replacing it with a Sunni, democratic government would reassure our friends in the region that Washington is determined to stand up to Iran when necessary. Even those who oppose involvement in the Syrian conflict allow that the loss of Assad would be a blow to the Islamic republic.
There is another strategic dimension to Assad’s ouster. Right now, the fighting in Syria risks spreading to the rest of the Middle East. Lebanon, intertwined with Syria for decades, has seen violence between pro- and anti-Assad factions. But Jordan and Iraq also risk being drawn in. Both governments rule fractious populations that could be moved to take on their U.S.-supported leaders. Far from increasing the odds of spillover, facilitating a resolution in Syria would probably contain the fighting and undercut outside groups such as al-Qaeda, which look to take the battle to Syria’s neighbors. This is the kind of confrontation with “violent extremism in all of its forms” that Obama promised in his 2009 speech in Cairo