Syria's Bashar al-Assad is looking more and more isolated, as his troops continue to violently repress the (mostly) peaceful protests against his government. The European Union is stepping up its economic sanctions, banning all Syrian oil; the Arab League is proposing elections for a new government; and now, even neighboring Turkey has had enough. "We've lost our confidence" in Assad, Turkish President Abdullah Gul said this week. "Today in the world there is no place for authoritarian administrations, one-party rule, closed regimes," and if such governments don't change, they can be "removed by force." Is the loss of a key economic and diplomatic ally the final straw for Assad?

This is proof Assad is toast: Assad's "knack for making enemies and losing friends" will be his undoing, says Rania Abouzeid at TIME. He could probably survive calls for his ouster from his Western foes, but he can't afford to lose key regional allies. Turkey has already reached the "breaking point" over Assad's brutal crackdown, and that may be enough to turn wavering Syrians against Assad.

"Unfriending Assad: Turkey, Iran, and even Hezbollah begin..."

Still, Iran hasn't abandoned Assad yet: As Syria's largest investor, "Turkey has some leverage," says Amir Taheri in the New York Post. And its push for a caretaker government to replace Assad has the backing of Europe and several Arab nations. But Iran "stands dead set against the scheme," and it has more leverage. As long as Syria is the focus of the "power struggle between regional rivals Turkey and Iran," Assad has a fighting chance to hang on.

"Syria: Turkey v. Iran"

One way or another, Assad is through: At this point, says Elliot Abrams in The Atlantic, it's just a question of when and how Assad goes. If hundreds of thousands of Syrian refugees flood into Turkey, that might give "the Turks the incentive they need to bring Bashar down." Alternatively, it could be a "palace coup" by Assad's Alawite cronies, or a mass defection by Sunni troops or the Christian business community.

"How will Syria's Assad fall?"