Saudi Arabia is pushing for Sunni Muslim Middle East countries to set aside differences over political Islam and focus on what it sees as more urgent threats from Irana nd Islamic State.
Its new monarch, King Salman, has used summits with leaders of all five Gulf Arab states, Jordan, Egypt and Turkey over the past 10 days to reinforce the need for unity and find a way to work around disagreements over the Muslim Brotherhood.
Saudi Arabia's deep-seated mistrust of the Islamist group is unchanged, diplomats say. But King Salman's approach to it is more nuanced than that of his predecessor King Abdullah, who died in January, and may include being more indulgent of allies who allow its members space to operate.
Last year Riyadh, along with the United Arab Emirates and Bahrain, withdrew its ambassador from Qatar over its links to the Brotherhood.
"The Saudis think maybe, if the Sunnis are on good terms, we can confront this. Salman is trying to consolidate the Sunni world and put differences over the Muslim Brotherhood on the back burner," said an Arab diplomat in the Gulf.
Riyadh's bigger concern is Shi'ite Iran. Its fears about the rising influence of its main regional enemy have grown recently as Tehran's Houthi allies seized swathes of Yemen and its commanders have aided Shi'ite militias fighting in Iraq.
Prospects are also growing of a deal between world powers and Iran on Tehran's disputed nuclear program, which might lift pressure on the Islamic republic. Saudi Arabia has watched nervously as its key ally, the United States, has reached out to pursue an agreement with Tehran.
U.S. Secretary of State John Kerry reassured the Saudis on Thursday that he was seeking no "grand bargain" with Iran, but Riyadh's worries over Washington's long-term commitment to the region underpin its desire for more Arab unity.
LURE OF ISLAMIC STATE
The second overarching concern for Riyadh is Islamic State. IS has called on Saudis to stage attacks inside the kingdom and some of its sympathizers assaulted a Shi'ite village in November, killing eight.
Riyadh fears the group's strong media messaging and appeal to strict Muslim ideology could appeal to disaffected young Saudis and challenge the ruling family's own legitimacy, which partly rests on its religious credentials.
But in seeking broader unity across the Arab world on the issue of political Islam, Saudi Arabia must address a deep regional rift. It runs between Sunni states who accept a Muslim Brotherhood presence, such as Qatar and Turkey, and those such as Egypt and the United Arab Emirates who, like Riyadh, describe it as a terrorist organization.
Those differences have come in the way of building a coherent response to regional crises, as attempts to address one problem after another have been diverted into arguments over Islamism.
"Saudi Arabia clearly doesn't want to be open to facing too many battles. IS and Iran are the enemy now, everything else can be put on hold," said a Western diplomat in the Gulf.
Salman's whirlwind of meetings was presented as a chance for the new monarch to discuss events with the region's leaders in greater detail than was possible when they went to Riyadh to pay respects after the death of Abdullah.
But while Salman did not directly push for a new Sunni bloc or lean on states to be more accommodating with those across the Muslim Brotherhood divide, he still opened the possibility of recalibrating relations to allow greater unity.
In his meeting with Egypt's President Abdel Fattah al-Sisi, for instance, he suggested Riyadh might reinvigorate its relations with other countries, an apparent reference to strengthening ties with Turkey, the Arab diplomat said.
But he also reassured Sisi, a close ally of the late Abdullah, that any attempts to undermine Egypt's security from elsewhere represented a red line for Saudi Arabia, and that any new moves Riyadh made would not be at Cairo's expense.
RIVAL IDEOLOGY
Nobody expects big changes to Saudi Arabia's position on the Muslim Brotherhood. The movement represents an ideological threat to Riyadh's dynastic system of rule, and its use of oaths of allegiance and secret meetings are anathema to the Saudis.
The Brotherhood was listed by Riyadh as a terrorist organization a year ago, with membership incurring long prison sentences, and both Western and Arab diplomats, and analysts said there was little prospect its status would change.
But Salman is less concerned than was Abdullah about the Brotherhood's role in other parts of the Middle East, such as in Yemen's Islah party or among Syrian rebel groups.
He is also more willing to allow the Brotherhood a role outside politics, for example by not stopping preachers affiliated to the movement from making public speeches on religious or social issues.
One sign of Salman's more pragmatic approach came during a conference in Mecca last week that brought together top Sunni clerics, including the Saudi grand mufti and the head of Egypt's al-Azhar University, to denounce terrorism.
Informed Saudis noted it was hosted by the Muslim World League, a body set up by Riyadh in the 1960s to build an Islamic bloc against radical secular ideologies, and used in the 1980s to bolster Sunnis against revolutionary Iran.
Under Abdullah, it fell out of favor partly because of its historical relationship with the Brotherhood, but Salman now seems prepared to use it again as an instrument to build Sunni solidarity. One of the delegates it invited was a senior member of a Doha-based group with close ties to the Brotherhood.
The change may partly reflect the personality of Salman, who is less uncompromising than was Abdullah, say Gulf insiders, and who is more willing to use any tools at his disposal to counter bigger threats.
All the leaders he met appeared to leave Riyadh confident that their relations with the new king would be strong.
Turkish President Tayyip Erdogan told reporters after his meeting that ties with Saudi Arabia seemed to be improving, Turkey's Hurriyet daily newspaper reported on Wednesday.
"My hopes increased that our bilateral relations will reach a much better place," he was quoted as saying.
But that did not lead him to be conciliatory towards Egypt, where he said political oppression might cause an explosion - exactly the sort of language that upsets Cairo.
