A deadline passed on Friday for Syria to agree to allow 500 observers into the country, which leaves the Arab League with little recourse but to slam the Assad regime with some harsh sanctions.

Reuters:

A deadline set by the Arab League for Syria to sign a deal allowing monitors into the country expired on Friday without any Syrian response.

Arab foreign ministers had said in Cairo on Thursday that unless Syria agreed to let the monitors in to assess progress of an Arab League plan to end eight months of bloodshed, officials would consider imposing sanctions on Saturday.

These could include halting flights, curbing trade and stopping deals with the central bank.

"The deadline has already ended, but the Arab League leaves the door open for Syria to reply by the end of the day and if a positive Syrian response comes on Friday, then the Arab League has no objection to agreeing to it," an Arab source said.

These sanctions would leave Syria not only isolated diplomatically, but also financially. The economy will crash without the central bank being able to conduct business with the world.

And Turkey is far more explicit in its threats:

Turkey on Friday said it could not tolerate any more violence and it was ready to take action with Arab powers if Assad failed to take steps toward ending the repression.

Turkish Foreign Minister Ahmet Davutoglu told a news conference in Ankara he hoped the Syrian government would give a positive response to the Arab League plan.

"If it doesn't, there are steps we can take in consultation with the Arab League," he said. "I want to say clearly we have no more tolerance for the bloodshed in Syria. The attitude of friendly and fraternal countries on this subject is clear."

Clearly, something is going to break in Syria soon. France has suggested setting up "humanitarian corridors" through which food and medicine can be delivered to civilians who are suffering. Those "corridors" could easily become conduits for stronger action if regional nations desired it.

Even the threat of force may be beneficial if it rouses the military to overthrow Assad. But that may be the least likely scenario because of the loyalties cemented to the regime in the officer corps. Regardless, it may come to Assad having no choice but to give in or leave, the latter course being the most desirable.