In case there is any doubt about who is in charge, guards patrolling the stretch of Syria around the Turkish border crossing here wear blue T-shirts stitched with "Islamic Front" patches.
Since opposition fighters first seized border crossings in 2012, their control of these posts — and by extension, the flow of people and commerce in and out of Syria — has been a barometer for which group was preeminent. Now the Islamic Front is trying to make it official, or as official as it can be with cheaply made signs and stitched-on patches that look like a bad home-economics project.
Last year, the two main arteries linking Syria and Turkey were under the nominal control of the Western-backed and largely secular
The Islamic Front has united some of the largest Islamist rebel groups fighting the government of Syrian President
It doesn't get along with all Islamists. In addition to fighting the Syrian government, it has battled fighters from the Islamic State of Iraq and Syria, the breakaway Al Qaeda group that in recent weeks conquered large swaths of northern and western Iraq.
All the same, Western nations that support the ouster of Assad are unlikely to cast their lot with a force that seeks to impose Islamic law, or sharia, and works closely with Al Qaeda-affiliated Al Nusra Front.
The Islamic Front seeks to achieve a goal that has eluded rebels in more than three years of fighting: creation of a professional opposition army. But its rebel groups are focused beyond that. They hope to create an Islamic state that would rule by some measure of sharia.
"We won't accept a secular state," said Mahmoud Haboosh, who heads the Front's political branch in Turkey.
Some of the Front's groups abandoned the FSA's Supreme Military Council, the military wing of the opposition Syrian National Coalition, which has committed to work for "a democratic and pluralistic civil state." Rebel groups in Syria long have chafed at the idea that a government formed by the expatriates of the coalition would be imposed on them. As the fighting has dragged on, rebel groups have become increasingly dominated by Islamists.
The growing hard-line nature of many in the opposition plays into Assad's argument that he is battling to protect Syria from Islamic militants, and is likely to make members of minority groups, such as Christians and Alawites, continue to fervently support him.
"The final goal is to have a united army for a united country," said the general commander of Ahrar al Sham, who uses the nom de guerre Sheik Abu Yazan. His group is a religiously conservative brigade that is among the founders of the Islamic Front in Aleppo. "But we don't want to be too idealistic. This might take years to accomplish, but we need to keep moving forward organizationally."
Despite its strength at the Turkish border, the Front has faced key setbacks farther into Syria.
In May, fighters with the Haq Brigade, one of the Front's member groups based in the central city of Homs, agreed to withdraw in a deal with the Assad government. It was a major blow to the opposition that once called Homs "the capital of the revolution."
The Front, which says it has nearly 70,000 fighters across Syria, also faces a challenge from a reenergized Free Syrian Army, which has gained access to a limited number of American-made antitank weapons.
President Obama asked Congress last week for $500 million to train and equip opposition fighters, who would be vetted by the U.S. to ensure they had no ties to militant Islamists. But it seemed unlikely any money would start flowing soon. And in a sign of the continuing troubles inside the U.S.-backed opposition coalition, it voided a decision by its leading official to disband the group's military command structure.
Islamic Front commanders acknowledge that uniting on the battlefield is of paramount importance if they hope to oust Assad.
"Once we unite we can make an entire military plan," said Samir Zaitoun, a former interior designer and now commander with Al Tawheed Brigade, another Front member group. "Before there would be battles in different areas and no one informed the other."
In January, for example, pro-government forces managed to break through a rebel siege of the Aleppo airport when various groups failed to coordinate, Zaitoun said. Fighters who were blocking the main highway were unable to hold off a government advance but didn't call for reinforcements.
"If we were just fighting the regime, we would be OK," said a Tawheed Brigade commander in Aleppo who uses the nom de guerre Abdulrazzaq Abu Bilal. He defected from the Syrian air force, in which he had served as a colonel. "But now that we are facing [fighters from] Iraq and Iran and Hezbollah, we need to fight smarter."
Resupply and reinforcement lines to the battle front have been merged, but the Islamic Front recently postponed an already-delayed deadline for full unification. Though the seven member groups now operate under the banner of the Front, they still mostly function independently.
The greatest challenge to the Front could come from within. Though it is defined as Islamist, its member groups hold somewhat different religious philosophies.
"I'm sort of reluctant to view them as a single unit," said Aron Lund, who has written on the Islamic Front and its member factions for the Carnegie Endowment's Syria in Crisis website.
Though some Front groups might end up merging successfully, others will probably eventually break away because of ideological differences or "big egos," Lund said.
"We have noticed that the Ahrar have some impulsive Islamist thinking," echoed Abu Bilal, explaining that the group described broadly as Salafist-militant adamantly rejects smoking — in a country where the majority of men smoke.
Even such a mundane issue could prove a significant obstacle to working together.
In Al Tawheed Brigade's media office in the Old City of Aleppo recently, the Arab version of "The Voice" was on TV as one spokesman was smoking an apple-flavored hookah and another was chain-smoking cigarettes.
Saleh Laila, puffing on the hookah, casually mentioned that once the individual media offices were united they would no longer be able to smoke openly.
"Is that true, Saleh?" Mustafa Sultan asked worriedly, his eyes widening.
"You'll have to go outside," Laila said.
"That's it, I'm going to form the National Progressives Front," Sultan said, taking another drag on his cigarette.
With its focus on future governance, the Front has been accused of seeking to exert control over all aspects of Syrian society.
"We had 40 years of people forcing their opinions on us, we don't need more of it," said Jamal Maarouf, head of the FSA Syrian Revolutionaries Front. "We don't want to be the alternative for the regime, it is my duty to oust the regime and then hand it over to the people."
The Front, he said, is under the misperception that it is the dominant rebel group in Syria. "They are not the entire Syrian revolution; they have a voice but not the only voice."
To combat criticism, the Front has taken a gentler public approach. Last month, it released a covenant calling for "a state of law, freedom and justice." While not intended to backtrack on ambitions for a constitution based on sharia, it was meant to distinguish the group from the Islamic State of Iraq and Syria, the Al Qaeda offshoot which is now engaged in more battles with other rebel groups than with the Syrian government.
"The international and regional situation is difficult and there are additional pressures from the propagandists who are against us," said Haboosh, the Front political leader. "So we wanted to respond to these accusations, we are moderates."
But its leaders are light on specifics. Haboosh said religious scholars would need to study whether women should be forced to wear the hijab and whether criminal sanctions should include whipping or the severing of hands.
"We have an idea for a modern Islamic state," Haboosh said.
He and other Front political leaders insist their system of governance would protect all sects and beliefs.
"We are [not] going to raise swords against them," said Muhammad Salim, a fellow member of the political branch.
But they draw the line at the political involvement of non-Sunni and non-Islamist groups.