If the mass protests in Iran succeed in bringing about change, it could produce a better neighbor – but also set a dangerous precedent for oppressive regimes.
The controversial move reverses the Bush administration's decision to withdraw its ambassador from Damascus in 2005.
After Sarkozy's speech, France divided over prospect of ban.
During speech Monday, Sarkozy suggested that the traditional female Islamic dress was a form of enslavement. But Obama backed freedom of religious expression in his Cairo speech.
Eyewitnesses say thousands of police and plainclothes militia members filled the streets to prevent rallies.