THE HOPES of Syrians for an end to the criminal repression by the regime of Bashar al-Assad now depend on the Arab League and the observer force it dispatched to the country this week. It is a very thin reed. The observers were originally meant to number 500, but have been pushed down to 150; 66 had arrived in the country by Wednesday. Their chief, Gen. Mustafa al-Dabi, is a former intelligence director for Sudanese President Omar al-Bashir, who himself is under international indictment for crimes against humanity.

On Tuesday, the mission visited Homs, the site of some of the bloodiest attacks by government tanks and troops against civilians. Reports said the observers were shadowed by government minders and did not enter neighborhoods where the worst violence has taken place. Meanwhile, another 17 people were reported killed in the city, including some of the thousands who tried to gather in a central square. Yet Gen. Dabi, who has been linked to the genocide in Darfur, was disconcertingly upbeat about what his team witnessed: “The situation seemed reassuring so far,” he told Reuters on Wednesday.

The Arab League faces a critical dilemma. On Nov. 2, it announced that Syria had accepted a number of stringent measures, including the withdrawal of military forces from cities, an end to violence against peaceful protesters, the release of all political prisoners and the admission of observers and foreign journalists. Were it to honestly implement all those steps, the Assad regime would promptly collapse, since it would be unable to contain the massive opposition movement that has grown up in the past nine months. So it wheedles and cheats and bargains for time. So far, it has won nearly two months of indulgence from the Arab governments, during which it has massacred hundreds more people and arrested thousands.

The deceptions continue. On Tuesday, Human Rights Watch reported that hundreds of prisoners had been transferred from detention in Homs to military bases, from which the observers are banned. It also said police identification cards were being issued to troops, so that the regime could claim to have withdrawn the army from the city without doing so. On Wednesday, Damascus announced that 750 prisoners had been released — but the opposition says tens of thousands remain in custody.

Gen. Dabi and his observers, and the Arab League as a whole, eventually must either report the truth about the regime’s continuing crimes or pretend they are not occurring. The United States and its allies, for their part, will have to decide whether to continue to rely on the Arab states to end the bloodshed in Syria or take more measures of their own. On Tuesday, the State Department hinted at the latter, saying in a statement that “if the Syrian regime continues to resist and disregard Arab League efforts, the international community will consider other means to protect Syrian civilians.” It did not say what those “other means” are. But if they are to stop the violence, they will have to be robust.