By Tom Perry and Suleiman Al-Khalidi
AMMAN (Reuters) - As Jordan joins a military campaign against Islamic State militants in Syria, tensions in Jerusalem pose a potentially bigger risk to a nation only slightly scathed by the turmoil sweeping the Middle East.
The U.S. ally has been alarmed and angered by recent Israeli actions at the sacred al-Aqsa compound in Jerusalem, where tensions are raising the prospect of a new Palestinian uprising that would add to the crises at Jordan's borders and may even spill into the kingdom.
For Jordanian King Abdullah, a majority of whose 7 million subjects are Palestinian, a one-day closure of al-Aqsa last week amounted to a personal affront: his Hashemite dynasty derives part of its legitimacy from its custodianship of the holy site.
"One of the major things that angers the Jordanian state and people is the Israeli behavior in Jerusalem. On the one hand we are trying to combat terrorism and extremism, and on the other hand we are confronted with this reckless behavior," said Mohammad Al-Momani, minister of state and government spokesman.
While Israel says it is sensitive to Jordan's views and blames extremists for stirring up trouble at the site, Amman is responding in unusually tough terms. It has even suggested the crisis could imperil the countries' 1994 peace treaty - an idea not heard from Amman during much bloodier Israeli-Palestinian flare-ups such as the July-August Gaza war.
This underlines just how seriously King Abdullah views a crisis that complicates his bid to keep his kingdom free from the type of turmoil that has toppled other Arab leaders and produced numerous civil wars in the region since 2011.
The timing could not be worse for Jordan, less than two months after it joined the air strikes on Syria that radical Islamists - including some in Jordan - are portraying as an attack on Islam rather than the Islamic State group.
Some Jordanians are not convinced by the logic of joining that U.S.-led war, fearing it could draw retaliation from Islamic militants in Jordan where - like elsewhere in the Muslim world - Islamic State is finding sympathizers and recruits.
The Jerusalem situation will provide King Abdullah's Islamist opponents, who range from jihadists to the mainstream Muslim Brotherhood, with new grounds to criticize the Western-backed leader unless he is seen to take a tough stance.
Jordan on Wednesday recalled its ambassador to Israel in protest, the first time it has done so since they made peace in 1994 though the post was also vacant for two periods since then.
"WATERED" WITH JORDANIAN BLOOD
Jordanian stewardship of the al-Aqsa compound was recognized in the 1994 peace treaty with Israel but dates back to 1924 when Palestinian leaders in Jerusalem granted custodianship to King Abdullah's great grandfather, Sharif Hussein.
The custodianship was reaffirmed in an agreement signed last year between the Palestinian Authority and King Abdullah. The area, which is also home to the Dome of the Rock, is known to Muslims as the Noble Sanctuary and to Jews as the Temple Mount.
A tinder-box for Israeli-Palestian conflict, it is the third holiest site in Islam and the holiest in Judaism. Several hundred Jordanian civil servants run the site. They allow Jews to visit, but not to pray there.
Israel closed the site last Thursday in response to the shooting of an Israeli-American far-right religious activist who has led a campaign for Jews to be allowed to pray there. It was reopened the next day after what Jordanian officials have described as a personal intervention by King Abdullah.
It was the first such closure at the site since 2000 - the year a visit to the site by the then Israeli opposition leader Ariel Sharon helped to ignite the second Palestinian Intifada.
King Abdullah has used unusually harsh language in recent criticism of Israel. He recently likened Islamic extremists to Zionist extremists.
In a speech this week, he said Jerusalem's soil was "watered by the blood and sacrifices of our martyrs" - a reference to Jordanian soldiers killed there fighting Israeli forces in the 1948 war that resulted in the establishment of Israel.
Jordan, which governed the West Bank including East Jerusalem from 1948 to 1967, would confront "through all available means, Israeli unilateral policies and measures in Jerusalem and preserve its Muslim and Christian holy sites".
"He's very annoyed and worried ... Jerusalem is everything," said a diplomat in Amman. "You can't overstate how important it is. It's the last thing they need. There's enough going on in Syria and Iraq and Jordan is impacted by both," he said.
"Whenever we have a big bout of extremism in the region then Jordan feels that wind blowing. That's cause for worry but not cause for thinking there will be short-term instability."
Israeli Prime Minister Benjamin Netanyahu has said the status quo of the al-Aqsa compound agreed with Jordan after the 1967 war will not be altered. But he is under pressure, even from within his own Likud Party. A far-right Likud member defied Netanyahu's calls for restraint by visiting the site on Sunday.
Israel says it wants stability in Jordan and is sensitive to its position. "Our greatest fear nowadays is that someone is trying to create disturbances on the Temple Mount in order to ignite the region, in order to harm both Jordan and Israel," Daniel Nevo, Israel's ambassador to Jordan told Israel Radio in an interview aired on Wednesday.
For Jordan, the specter of another big flare-up of the conflict between Israel and Palestinians brings risks unlike those arising from the expansion of Islamic State in Syria and Iraq. Jordan has received waves of Palestinian refugees in the 1948 and 1967 Middle East wars, and restive Palestinian nationalism has been a source of concern for decades.
Add to that socioeconomic malaise - unemployment is running at 11.4 percent but unofficial figures put it at twice that level - and slow pace of political reform, and Jordan faces the same combustible mix that set off the Arab uprisings in 2011.
On a clear night, the lights of Jerusalem can be seen from the Amman outskirts, proximity that also sets the Israeli-Palestinian conflict apart from the wars in Syria and Iraq.
Some of Amman's poorer districts are actually Palestinian refugee camps that with time have become permanent residential areas, home to the descendents of Palestinians forced to flee by wars in 1948 and 1967. Jerusalem means much more to these Palestinian Jordanians than the war against Islamic State.
"In Syria, people are facing injustice and want to be free from injustice. But Palestine and Jerusalem are occupied and usurped land," said Thaer Dawood, 46, an Amman shopkeeper whose family hail from a village near Ramallah in the West Bank.
"You don't quite know what is going to happen because you have a lot people from the West Bank here. Nobody here will consent to what is happening in Palestine," he said, speaking at a coffee shop in a mostly Palestinian district of Amman.
Jordan managed to navigate the last two Palestinian uprisings without major instability.
"We are doing a good job in maintaining peace and security," Momani, the minister, said. "More and more Jordanians are subscribing to the idea that stability and security is the oil of this country. That is why we protect it dearly."
But combined with Jordan's internal challenges -unemployment, poverty and a lack of political inclusiveness - conflict in Jerusalem will only make it easier for groups like Islamic State to recruit.
"The public protests (over Jerusalem) will be strong, but the frustrations inside individuals will be much stronger," said Taher al-Masry, a former Jordanian prime minister from a prominent Palestinian family.
"The danger from Daesh (Islamic State) is not from it coming over the borders, but from feelings or frustrations concerning the deteriorating economic conditions."
(Writing by Tom Perry; editing by Anna Willard)