They’re happy, but they’re not happy. Pleased that President Obama announced last night that the US recognises the new Syrian opposition coalition as the “legitimate representative of the Syrian people.” Unhappy that one of the fiercest fighting forces on the ground, Jabhat al-Nusra, has been designated by the USA as a terrorist group.

Here in Marrakech, where the international Friends of Syria group is meeting, the Syrian National Coalition, which formed last month, is trying to re-present itself as a government in waiting, and a civilian authority which guides the newly formed High Military Command of rebel fighters.

To them it is President Bashar al-Assad’s forces that are the terrorists, not the jihadi groups fighting alongside the Free Syrian Army to overthrow him.

“There is nothing wrong with fighting in the name of Islam,” said the coalition leader, Ahmed Moaz al-Khatib, a moderate imam, in his speech to assembled ministers and diplomats. He requested the Americans to reconsider their decision.

“We will work with everybody on the ground who has an agenda which includes ending the suffering of the Syrian people,” said Yaser Tabbara, a coalition spokesman. “If al-Nusra is on the same page, they will be dealt with using dialogue and containment.”

In other words, you Americans can call them terrorists if you like but they’re more useful to us than you are. The Americans are not giving the Syrian opposition weapons, while al-Nusra are fighting on the same side.

The opposition regards Syrians from al-Nusra, who fought the Americans as part of Al Qaeda in Iraq, not as a threat but an asset. Their experience and ideology has turned them into some of the fiercest and most effective fighters, and they’re getting weapons from private donors in the Gulf.

As winter approaches, the fighting is getting more intense. Two million Syrians have been displaced within the country. According to Mr Tabbara, the rebels now control enough territory – especially in the north around Aleppo – to administer a ‘liberated zone’. They need, he says, US$500 million a month to pay salaries, feed people and attempt to establish some kind of normal life.

The meeting in Marrakech is expected to establish a humanitarian fund.That may alleviate some suffering but it won’t solve the fundamental problem: the US and other western countries, including Britain, want the overthrow of Bashar al-Assad.

By backing the new coalition they hope to promote what they see as a ‘moderate’ replacement administration. But on the ground, the jihadis are getting stronger, and the opposition cannot afford to reject them.

Follow Lindsey on Twitter via @lindseyhilsum