* Foreign fighters draw respect and fear among Syrians
* Jihadists ready to fight even rebels to achieve caliphate
* Radicals impose tough discipline unlike some FSA units
* Some Syrians seem prepared to accept gruesome retribution
By Yara Bayoumy
ALEPPO, Syria, Jan 11 (Reuters) - Huddled around a fire in a bombed-out building in Aleppo, foreign jihadists say they are fighting for a radical Islamic state in Syria - whether local rebels trying to topple President Bashar al-Assad like it or not.
Among their fellow revolutionaries and civilians, these foreigners draw both respect for their iron discipline and fear that if Assad falls, they may turn on former allies to complete the struggle for an Islamic caliphate.
One Turkish fighter in the devastated Aleppo district of Karm al-Jabal expressed an unbending determination to achieve a state under Sharia Islamic law that worries many Syrians, the West and even regional backers of the anti-Assad rebellion.
"Syria...will be an Islamic and Sharia state and we will not accept anything else. Democracy and secularism are completely rejected," said the fighter, who called himself Khattab.
Sporting a shaggy beard and with an AK-47 slung over his shoulder, he warned anyone who might stand in the way. "We will fight them, even if they are among the revolutionaries or anyone else," said Khattab, who left his job as a driver to fight for two years in Afghanistan before moving to Syria six months ago.
A member of the Jundollah rebel unit, Khattab has little knowledge of Arabic - he spoke in the rubble-strewn building through a Syrian translator - and refused to be filmed or photographed for fear of being identified back in Turkey.
The government of Turkey is itself Islamist but strongly opposes the radical ideology of Khattab and the militants who are rising among the rebel groups fighting Assad in a conflict that has claimed at least 60,000 lives.
The United States designated al-Qaeda's affiliate in Syria, al-Nusra Front, as a terrorist organisation in December after it claimed responsibility for bombings in Damascus and Aleppo.
However, many rebels and Aleppo residents say fear of the jihadists is overblown. The West is exploiting it to justify not sending desperately-needed arms to the rebels, they say, prolonging Assad's hold on power.
In Aleppo, Syria's biggest city, the radicals' influence is obvious. Many rebels drive through the shattered streets in cars emblazoned with black Islamist flags carrying religious slogans.
Accounts differ on how much radical groups coordinate with units of the mainstream rebel Free Syrian Army (FSA). Many rebels praise the skills of the jihadists - often honed in Afghanistan or Iraq - saying they are among the bravest fighters although they tend to be reclusive.
Some, however, are new recruits in the holy war in a country they call Al-Sham, recalling a greater Syria established after the Muslim conquest over 1,300 years ago.
One such is Abu al-Harith, a stocky, fair, 27-year-old from Azerbaijan who spoke at a rebel base in Karm al-Jabal, a district so damaged it seems to have suffered an earthquake.
"This is my first time to embark on a Jihad because ... there was no one worse than Bashar. Even Stalin was merciful compared with him," said the young man, who wore a ski mask and had a black badge bearing an Islamic religious slogan sewn onto his green fatigues.
Nevertheless, there is concern about the post-Assad vision of these foreign radicals - whose numbers are difficult to assess - and whose rejection of a future democratic state may sit uneasily with many Syrians fighting authoritarian rule.
Some jihadists distrust the Free Syrian Army, an army in name only composed of mostly local Sunni Muslim fighters and army defectors. Likewise they see little difference between the West and regional Islamic countries which back the FSA.
"All this talk about freedom, democracy and the secular state and a state of open freedoms like America and the European system - Islamists do not care about this talk at all," said 25-year-old Abu Muawiyah, a skinny fighter who said he was from the Aleppo countryside and translated for the foreigners.
"There are some fighting factions like the Free Syrian Army, who have links to other countries like Turkey, Saudi Arabia and Qatar and these countries have links with the controlling pole, which is the United States," he said. "America is against anything Islamic. That is obvious to everyone."
Not all foreign fighters have a radical vision, and they are welcomed heartily by Syrian fighters. Abu Ahmed al-Libi, who fought to overthrow Muammar Gaddafi in 2011, said he came to Syria with a band of 15 Libyans eight months ago.
A large man who had an easy camaraderie with Syrian fighters in his unit, he shook hands with a female reporter - a rarity among even mainstream Islamist groups in Syria. Libi said he had trained 40 Syrians in Libya before bringing them over, and estimated the number of Libyan fighters in Syria at about 200.
While Washington has recognised the rebels' National Coalition as the sole representative of Syria, its designation of al-Nusra Front as a terrorist organisation has angered many rebel leaders. They say the group, whether it espouses extremist ideology or not, is fighting the same enemy as they are.
Al-Nusra Front has a reputation for being extremely disciplined, and it is hard to find many people who will criticise it. Abu Abdo, a fighter on one of the many frontlines in Aleppo, said he had tried to join the group but was rejected because he was a smoker.
Colonel Abduljabbar Oqaidi, who heads the military revolutionary council in Aleppo province, defended al-Nusra Front. "We may differ with them on their thought," he told Reuters recently, but he rejected Washington's designation.
"They're fierce and loyal ... And at the end of the day they're fighting the regime with us. And we have not seen their extremism, they have not done anything that proves they are terrorists," he said. "Anyone fighting the regime is a mujahid and a revolutionary and we kiss their forehead," said Oqaidi, adding that their numbers were not more than 500 in Aleppo.
By contrast, support for the Free Syrian Army has eroded among some Aleppians due to some cases of looting.
"The cleanest unit on the ground, with no corruption within its ranks, is the al-Nusra Front. The group now has a popular base. Maybe their ideology is distant from the people's but they started liking al-Nusra front because they are just," said Abu Ahmed, who leads an Aleppo unit of the large al-Tawheed brigade.
"The fear surrounding the Nusra Front is down to intimidation by the media," he said. "My ideology is not the same as the Nusra Front but I have to say what I've experienced from them."
Fears of internecine conflict remain. A commander of al-Farouq Brigades, one of Syria's largest rebel groups, was shot dead on Wednesday in what rebel sources said may have been in revenge for the killing of an al-Nusra Front leader.
Some rebels see a more ominous future. "We're scared that after the fall of the regime, they will try to impose their views on the Syrian people. Their goal is for Syria to be an Islamic state and the Free Syrian Army is the opposite of that," said a 24-year-old rebel fighter in trainers and tracksuit pants who goes by the name Saqr Idlib.
Walking through a destroyed part of the al-Sukkari district in Aleppo, the fighter puffed worriedly on a cigarette: "We're scared there'll be problems by al-Nusra Front and other groups like them after the fall of the regime."
By contrast, Abu Ahmed said he had no fear of a future conflict and his wife - who wears a headscarf but does not cover her face - chimed in: "Al-Nusra Front's ideology is Islamic and at the end of the day, we are Muslims."
While Syria's uprising has been led by Sunnis, minority Christians and members of Assad's Alawite sect - an offshoot of Shi'ite Islam - had nothing to worry about, said Adnan Abu Raad as he watched gravediggers shovel dirt in the town of Azaz near the Turkish border.
"Any boy, child or women will say we want an Islamic state only. And there is no difference between Sunni, Christian or Alawite. Just peace and security for all," Abu Raad said.
At least some people in Aleppo seem willing to tolerate even gruesome retribution by the jihadists. "Yes, they have the sword and beheading, but only for those people who deserve it," said Hadi, a bearded rebel who spoke in the corridor of a bombed-out building that served as a gateway to a frontline.