The turmoil hitting Saudi Arabia's neighbor Yemen will pose the first big test for King Salman, and provide a glimpse as to whether his approach to hotspots in a fragmenting region will differ from that of his late brother.
Yemen is at risk of breaking up with the ascent of the Houthi movement, a group whose main strategic alliance is with Riyadh's great regional foe Iran, in a country also home to Sunni al Qaeda's most active affiliate.
In that respect, Yemen reflects what has happened across the Middle East, with Tehran's Shi'ite Muslim allies dominating war-torn Iraq and Syria, and Saudi Arabia attempting to back Sunni groups without bolstering its Islamist militant enemies.
Under King Abdullah, Saudi Arabia constructed a dual-track regional policy of attempting to contain Iranian influence while at the same time opposing the growth of Sunni political Islam which it saw as an ideological threat to dynastic rule.
That does not look likely to change, although the arrival of a younger man may make for a more active approach, possibly including a new effort to reach out and engage local players in Yemen, analysts say.
Foreign policy in Saudi Arabia is a team job for the clique of ruling princes, even though it is the king who has the ultimate say. Salman was an integral part of Abdullah's team, and he brings many of the same princes into his own.
"They are not going to get involved in a quagmire. I don't think there will be major change. It's about containment," said a Saudi close to policymakers.
However, the fact that he is 11 years younger than Abdullah, and able to give more direct attention to the big issues, may mean Saudi policy will become more proactive, particularly in Yemen, where there have been years of quiet disengagement.
"I think they're going to go to Yemen with open eyes and will try to contact all parties in the crisis and not exclude anyone," said Mustafa Alani, a security expert with close ties to the kingdom's Interior Ministry.
After decades buying the support of tribes, politicians and clerics in Yemen, the Al Saud watched as their patronage network fell apart during a 2011 uprising and have now fallen back on a defensive security policy.
Riyadh is constructing a tough series of border defenses to insulate itself from its turbulent neighbor and has cut off funding to Sanaa, hoping that will eventually persuade Yemen's new rulers to compromise.
FOREIGN EXPERIENCE
Sunday editions of the main Saudi newspapers ran at more than triple length, as companies bought full-page adverts to express their condolences for the late Abdullah and allegiance to King Salman and his two designated heirs.
Both Crown Prince Muqrin, who was intelligence chief from 2005-12 and whose mother was Yemeni, and Deputy Crown Prince Mohammed bin Nayef, who is Interior Minister, have been closely involved in Saudi Arabia's Yemen policy.
It is Prince Mohammed, whose main focus is on assuring the kingdom's domestic security, who has been most prominent in shaping its Yemen policy in recent years, working closely with Sanaa against al Qaeda, but also strengthening border defenses.
"The Saudis are looking for a real partner. They are very, very confused," said a source close to Yemen's government, adding that they would not support any government that the Houthis shared in.
A more proactive Yemen policy might mean reaching out to former leader Ali Abdullah Saleh and the Islah party, erstwhile allies of Riyadh but whose unreliable track record and ties to the Muslim Brotherhood later became anathema to Abdullah.
Salman may feel less worried about Islah, which beside the Brotherhood is also tied to tribal players and street leaders of the 2011 uprising, and may consequently adjust Riyadh's attitude towards it as one potential partner in Yemen, say analysts.
Any change in attitude towards Islah would be closely watched by Egypt, where President Abdel Fatteh el Sisi has ruthlessly crushed the Brotherhood with the vocal encouragement of Abdullah and still seeks Saudi economic support.
However, Riyadh views Yemeni politics as distinct from those of the wider region, so its behavior towards Islah or the Houthis might not reflect wider stances towards the Brotherhood or Iran.
"I don't think their policy towards Yemen is reflective of their policy towards the world. It's their back yard and very particularistic and idiosyncratic," said Bernard Haykel, professor of near east studies at Princeton.
IRAN RIFT
There seems little chance that the region-wide tussle for power with Iran will abate, despite brief visits by its Foreign Minister Mohammad Javad Zarif on Friday and Saturday for Abdullah's funeral and the formal paying of respects.
Iran's President Hassan Rouhani has pushed for better ties between the two countries, whose rivalry has been a factor in conflicts across the Middle East. Zarif and Saudi Foreign Minister Prince Saud al-Faisal met at the United Nations General Assembly in New York in September.
Tehran has attacked Prince Saud for his harsh words towards Iran's policy in Syria, and diplomats say the Islamic republic views him as a hardliner who is obstructing detente.
However, Prince Saud, who had an operation in the United States on Sunday, state media reported, does not set foreign policy alone. While his voice is important, he just one among several top princes who contribute, with the king having the final say.
The senior ranks of the Al Saud regard Tehran's continued support for Syrian President Bashar al-Assad as an immovable obstacle to rapprochement, and the crisis in Yemen has only served to further harden them against Iran's call for detente.
"Salman is quite hawkish on Iran. He's personally quite hawkish. The Iranians would have to do a lot for him to change his policy," said Haykel.
