Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.

The death of Saudi Arabia’s King Abdullah has put the spotlight on who is succeeding the man Forbes magazine called the 11th most powerful person in the world. The key U.S. ally faces challenges including extremist threats, Iranian muscle-flexing and the economic impact of the plummeting oil prices. Here's how some experts think the country may deal with the choppy waters.

What do we know about the succession and successor(s)?

King Abdullah’s successor is his half-brother, Deputy Prime Minister Salman bin Abdul-Aziz. The 79-year-old former defense minister is one of the sons of Hassa al-Sudairi, who was thought to be the late king’s favorite wife. He and his brothers are known as the Sudairi Seven, and considered the inner circle of the country’s elite.

Within the kingdom, Salman is seen as intelligent and skilled at balancing the competing pressures of modernization and tradition, according to prominent philosopher Nayef al-Rodhan.

"He is a wise leader who understands the importance of his country to regional and global order," al-Rohan said.

Some say the new king may be more conservative than Abdullah, and may try to reverse some of the limited political and social reforms the current king pushed, such as moves to allow women to be appointed to the country’s parliament.

Salman is aged in his 80s and is widely thought to be in bad health — something that Saudi officials categorically deny. King Abdullah surprised many when he took the unusual step of appointing a deputy crown prince in March — Prince Muqrin bin Abdul-Aziz, another half-brother who is a former head of Saudi intelligence.

In his late 60s, Prince Muqrin is no young upstart, although he does represent a generational change. And like with Prince Salman, little is known about the specific policies the deputy crown prince might pursue.

‘Enormous challenges’ ahead?

Let our news meet your inbox. The news and stories that matters, delivered weekday mornings. This site is protected by recaptcha

“The Saudis are in turbulent waters in the region, and have faced a hostile and unknown environment and are still dealing with the aftershocks of the Arab Spring,” according to Frederic Wehrey of the Middle East Program at the Carnegie Endowment for International Peace. “There are enormous challenges.”

ISIS extremists that have taken swathes of Iraq and Syria and their allure to certain disenfranchised members of Saudi Arabian society is seen as a huge threat to the establishment, he said.

“They take the possibility of ISIS appeal among Saudi youth seriously,” Wehrey added.

So the new ruler will have his work cut out for him, said Jim Phillips, senior research fellow for Middle Eastern affairs at conservative think tank the Heritage Foundation.

As custodian of Islam's two holiest cities, Mecca and Medina, Saudi Arabia’s ruler will most likely continue a “Faustian bargain” with the country’s extremely conservative Wahhabi religious establishment, and “continue to lavishly fund them.”

"There is a looming economic crisis on the horizon"

“I think the older generation in Saudi Arabia has to be acutely aware that the basis of their legitimacy is increasingly being challenged by radical Islamist militants and they must take action to drain away the support for those movements,” Phillips added.

Another challenge the new ruler will face is how to steer the oil-dependent economy through a period of low oil prices. Crude prices have plunged almost 60 percent over the last six months. According to the Financial Times, Saudi Arabia is forecast to reduce state spending by 18 percent this year — cuts that are tied to low oil prices.

“They will curtail their spending in region, foreign aid to Egypt, but leave subsidies and welfare benefits untouched,” Wehrey said. “There is a looming economic crisis on the horizon.”

Shiite Muslim Iran will continue to be a challenge for Saudi Arabia’s Sunni Muslim new ruler. The Islamic Republic of Iran holds sway over the Shiite-dominated government of Iraq, Hezbollah in Lebanon and Shiite Houthi rebels rampaging through neighboring Yemen.

“Saudi Arabia has not been able to put a mechanism in place to counter Iranian influence in the region, and can’t do it at this stage, because of Iranian troops on the ground and rapprochement to the U.S.” according to Musa Shteiwi, the director of the Center for Strategic Studies at the University of Jordan.

So what about the United States?

This thawing of relations between the United States and Iran — thanks to the ongoing talks over Tehran’s contested nuclear program — has disappointed many in Saudi Arabia. But that is unlikely to bring about any radical change in alliances.

“They don’t trust the Americans on this issue because they also think the Americans have made the wrong decision,” said Jane Kinninmont, a senior research fellow and deputy head of the Middle East and North Africa program at Chatham House, an international think tank based in London.

No major break is seen on the horizon, however.

“The (Saudi Arabia-Iran) relationship has had a good and long history, but is not what it used to be,” Salman Sheikh, the directory of the Brookings Doha Center, a center-left think tank said, adding: “I just wonder how strong relations are between this administration and the Saudi family, this is most crucial period for the next decade.”