The New York Times reports: Lakhdar Brahimi, the international envoy trying to broker a peace deal in Syria, announced on Wednesday a tentative cease-fire between the two sides to mark the main Muslim holiday of the year, but numerous do-it-yourself aspects of the plan immediately called into question whether it would quiet any fighting.

Open uncertainties included the time frame of what was designed to be a temporary cease-fire for the Id al-Adha, the Islamic Feast of Sacrifice, expected to start Friday for much of the Muslim world. Different nations and different sects can observe the holiday for anywhere from one to five days, however, so it was not clear exactly how long any truce should last.

On a more basic level, it was not quite clear who would respect it among the warring parties. Syrian state television announced that Damascus was studying the proposal and would make an announcement on Thursday, according to wire service reports. Various leaders among the fractious rebels issued their own statements saying they doubted it would hold.

It was also unclear that there would be anyone around to police it — the United Nations withdrew its observers last summer and would probably not be able to deploy new ones in 48 hours.

Mr. Brahimi seemed to be relying on the fact that both sides in the civil war, which grew out of a peaceful protest movement that started in March 2011, would respect it all on their own.