The American-led coalition against Isil suffered a blow yesterday (Wednesday) after the United Arab Emirates pulled out of air strikes following the murder of the Jordanian pilot Lt Moaz al-Kasaesbeh.
Lt Kasaesbeh was shown in a video put online on Tuesday by Islamic State of Iraq and the Levant being burned alive in retribution for his part in bombing raids.
Emirati leaders were said to be angry at the lack of coalition air rescue facilities, which they said put their own pilots at risk of the same fate as Lt Kasaesbeh.
UAE officials suggested they were unhappy with the way the coalition was being led, particularly in Iraq, where it is effectively providing air cover for ground operations that contain a strong presence of Iranian-backed militias and Iranian military advisers.
The UAE regards Iran with great suspicion, as a regional rival.
Its presence in the coalition is important to show that Isil's fellow Sunni Arabs are among those fighting the group.
An Emirati officer, Major Mariam al-Mansouri, a rare Arab female fighter pilot who took part in the raids, was also an early media star of the campaign.
But it is also a sensitive issue for the UAE, which in Dubai and Abu Dhabi have two of the most westernised cities in the region, but was also home to two of the September 11 attackers.
Its complaints were issued before the video released on Tuesday confirmed Lt Kasaesbeh's gruesome death, but after his jet was downed and he was captured on Dec 24.
It seems unlikely that any rescue mission could have been attempted, however close American Osprey rescue helicopters were located, given the speed with which he was picked up by Isil fighters.
However, the Emiratis demanded that Ospreys be located in northern Iraq, near the site of most raids, rather than in Kuwait, as at present.
The shock caused by the images of Lt Kasaesbeh's death galvanised support for the coalition in Arab countries where there had previously been some popular opposition, including Jordan itself.
The country reacted immediately by executing two Isil-linked jihadists before dawn yesterday, including Sajida al-Rishawi. She was the Iraqi woman failed suicide bomber whom Isil demanded in exchange for the release of Kenji Goto, the Japanese journalist being held hostage. After Jordan refused to release her without proof of life for Lt Kasaesbeh, Goto was beheaded.
Rishawi was on death row for her part in the mass suicide bombing of three hotels in the Jordanian capital, Amman, which killed 57 people in 2005. Her own suicide vest failed to detonate. The other prisoner was Ziad al-Karbouli, another Iraqi who had been convicted of murder and being a member of al-Qaeda.
Both were hanged at Swaqa prison south of Amman at 4am.
Jordan's King Abdullah II promised a "severe" response yesterday, having cut short a visit to the United States. "The blood of martyr Moaz al-Kasaesbeh will not be in vain and the response of Jordan and its army after what happened to our dear son will be severe," he said.
There were brief protests criticising the government's handling of the case in Lt Kasaesbeh's home town of Karak on Tuesday night.
But there was a stronger mood of unity throughout the country in the face of the killing. "For the first time, I see unprecedented unity on social media of both Jordanian and Arab thought against this crime," a well-known Jordanian blogger, Deema Alam al-Deen, said. "There are people, and I'm one of them, who have believed that the war against terrorism was our war ever since the 2005 bombing. But some people who used to think that this was not our war... are now convinced that Jordan must act."
Marwan Shehadeh, a Jordanian expert on extremist groups, warned that the new spirit of unity behind King Abdullah II might be short-lived. "Now people are sad because of the brutality of the death but I think the voices will rise up soon to stop Jordanian participation in the coalition," he said. He did not think the "few thousand" Isil supporters in the country were strong enough to be a serious security threat, but he expected revenge attacks.
Isil defended its actions, releasing online a theological justification for the burning of prisoners after Muslim scholars across the region said it was not sanctioned in the Koran. An Isil-linked theologian said that the Koran accepted "eye-for-eye" punishment, and that burning was a suitable method for dealing with someone who dropped bombs.
Other Islamic leaders, including Yusef al-Qaradawi, seen as the spiritual leader worldwide of the Muslim Brotherhood, said the Prophet Mohammed urged humane treatment of prisoners.
Ahmed el-Tayeb, the Grand Imam of Al-Azhar University in Cairo, the most revered school of learning in the Arab World to which many Sunni Muslims turn for theological guidance, said harsh punishment should be reserved for those who carried out the burning.
"Islam forbids killing of the innocent human soul. It forbids mutilating the human soul by burning or in any other way even during wars against an enemy that attacks you," he said.