Syria is locked in an ominous and violent stalemate: With overwhelming firepower and a willingness to kill, President Bashar al-Assad could hold on to power for months or even years, keeping the opposition from controlling any territory and denying it breathing space to develop a coherent, effective leadership, according to analysts, diplomats and Syrians involved in the uprising.

Syrians and regional analysts say sheer force alone is unlikely to eradicate what has become a diffuse and unpredictable insurgency, one able to strike out even after the government has used crushing force against centers of resistance like Homs, Idlib and Dara’a. Broad areas of the country are hostile territory for government troops, and attackers have managed to hit centers of power, even in the capital, Damascus…

Many Syrians say that Mr. Assad cannot afford to stop shooting and can never go back to ruling as he did before, when his authority stemmed from the bonds of sect, business interests and fear. If he dials back his repression, Syrians of many political stripes say with certainty, citizens will demand his ouster…

The security officials who might be able to overthrow him now see their fates intertwined with his. The public has suffered too much to be satisfied with a coup alone; they would seek the entire security system’s downfall and, possibly, revenge.