On a trip to Syria that spanned most of the month of November, a journalist found Nusra’s fighters on every frontline he visited.

In the country’s largest city of Aleppo, they were advancing on the army to try to take key intersections. In Maarat al Numan, a strategic city on the highway between Aleppo and Damascus, they were laying siege to a military base. In Ras al Ayn, in the country’s northeast, they captured a strategic border post, allegedly summarily executing a number of Syrian soldiers they had trapped on a base there in the process. In Deir al Zour province, in the country’s southeast, they were at the fore as rebels captured parts of Syria’s oil infrastructure and laid siege to an artillery base near the city of Mayadeen in hopes of capturing the weapons inside.

“Our financial support is greater than other groups, and our faith makes us more effective fighters,” said Mahmoud, explaining why the group had grown so quickly. He said the financial support came from individual donors, not directly from any government.

The mujahedeen groups also appear to have clearer structures than the military councils, whose leadership is sometimes less than obvious as newer defectors of higher rank demand control from less senior officers who’ve been fighting against Assad longer.

Car bombings have also increasingly killed civilians in Damascus neighborhoods sympathetic to the government. The first operation Mahmoud’s group supported was a suicide bombing by a Libyan man against an army base north of here.

Mahmoud said he saw no reason to hold elections if Assad falls.

“Eighty percent of Syrians want Islamic law,” he said.

Many fighters said they were aware of the accusations about Nusra’s links to al Qaida. But they generally discount the importance of those ties when speaking with journalists.

“In Europe, they consider all Muslims terrorists, not only Jabhat al Nusra,” Mahmoud said.

Still, there are moments when Nusra’s ideology shines through.

“When we finish with Assad, we will fight the U.S.!” one Nusra fighter shouted in the northeastern Syrian city of Ras al Ayn when he was told an American journalist present. He laughed as he said it and then got into a van and drove off, leaving the journalist unable to ask whether it had been a joke.

In Ras al Ayn, the burning of a liquor store by Nusra fighters frightened Syrian Kurds and Christians living there, and the group has come into direct confrontation with Kurdish militia members in the area who’ve said they are willing to negotiate with moderate rebels but will not allow groups like Nusra into the territory they hold.

There are tensions developing between local military councils and Nusra and other non-aligned groups. On Saturday, one group planning an attack in the Qalat al Mudiq area was asked by the military council to call it off, to avoid endangering a local truce that holds in the city.

In the eastern province of Deir al Zour, Muhammed Mustafa Aboud, the military council commander, said that in meetings with U.S. officials in Turkey and Jordan, the main concerns had been “Nusra and al Qaida.”

“We say to them they are small groups and they are not very powerful and it’s your fault because if you had supported FSA they wouldn’t be here now,” Aboud said. “Eighty percent of Syrians are moderate Muslims . . . the West is too afraid of these groups.”