IBLIL, Syria — The airstrikes resumed at 7:30 a.m., beginning with a rolling series of explosions in the village of Zoghba. An extended roar shook the northern Hama Plain.

In nearby Iblil, rebel fighters listened knowingly. If the pattern held, shells and rockets would soon follow — and hundreds of opposition fighters in villages they had recently claimed would face another punishing day.

Roughly six weeks ago, as foreign governments were focused on whether chemical weapons had been used in Syria’s civil war, several rebel groups made a decision blending boldness and risk. Eager to break a painful near-stalemate that has settled over the war since late last summer, they opened a front here on the arid flatlands east of the Aleppo-Damascus highway.

At first the rebel thrust moved swiftly. But as the fight has unfolded, the battle here has assumed the war’s seesawing and bloody rhythm, capturing many of the dynamics of a conflict exhausting its mismatched adversaries, and putting the nation on a path toward disintegration.