National leaders do, on occasion, lose the plot when in office. But seldom do they gain top positions when their minds have already gone. The elevation of Crown Prince Salman to the Saudi throne, following the death of King Abdullah on Thursday, could prove a live experiment in whether such a scenario is viable. The Economist has reported that the 79-year-old Saudi leader may be suffering from dementia. Former top CIA analyst Bruce Riedel has written that Salman is “not up to the job.” At this stage, speculation about Salman's health remains unconfirmed by Saudi authorities. But keep in mind that Saudi Arabia isn't just any country; the kingdom is the leader of the Islamic world, a leader of the Arab world, and, by virtue of being the world's largest oil exporter, a major economic player. So hold on. The ride ahead could be rough.

Saudi Arabia now faces two principal challenges. The short-term one is that the kingdom’s leaders believe they are threatened on all sides. To the south, pro-Iranian tribesmen have taken over Sanaa, the capital of neighboring Yemen (a chaotic Yemen is nothing new, but it would be embarrassing and destabilizing for Saudi Arabia if Yemen’s northern region becomes a lawless haven for jihadists). ISIS is probing the nation’s northern frontier; three Saudi border guards were killed along the Iraqi-Saudi border on January 5. And it looks as though the despised Iran, across the Persian Gulf, is being offered a tantalizing nuclear deal by the United States, hitherto Saudi Arabia’s trusted security guarantor. It isn’t obvious how Saudi Arabia can best respond to these developing crises, but it is obvious that it will need a shrewd leader to craft those responses.

In the longer term, Salman’s decision to accept his half brother and Deputy Crown Prince Muqrin as his own crown prince, or designated successor, doesn’t resolve how royal succession will play out following Muqrin. With no more sons of the kingdom's founder, Ibn Saud, available, which line of grandsons will be tapped as a source of future kings? The news that grandson Prince Muhammad bin Nayef has become the new deputy crown prince does not fully answer this critical question. Are all the other grandsons going to simply accept being banished into obscurity? I doubt it. MbN, as he is known, is dour, not dynamic. His father wasn’t a king. He is favored by U.S. counterterrorism officials, but that is not necessarily a plus in his country, where it is better to be regarded as pro-Saudi than pro-American. Still, as a survivor of the world’s first rectal suicide bomb (a jihadist, claiming he wanted to surrender to MbN, managed to circumvent a security screening), he at least has “luck.”

As the few remaining sons of Ibn Saud grow older and more infirm, the weakness of Ibn Saud’s succession mechanism has grown more glaring. Successive Saudi kings—Saud, Faisal, Khalid, Fahd, Abdullah, now Salman—have become progressively older at the point of gaining the throne, and their reigns have become more dominated by health issues than ideas about guiding the kingdom through turbulence, both foreign and domestic. Competition among Ibn Saud’s sons has often been vicious. There is little reason to expect that rivalry among his grandsons will be any less intense, despite all the efforts to publicly convey a sense of calm in the House of Saud.

Given Salman’s reported health problems, who is going to actually rule Saudi Arabia? The king, after all, is notionally also the prime minister and top decision-maker. The simple answer is Salman’s camp, but the makeup of this camp is murky, and Salman will likely be suspicious of those who served loyally for his predecessor. The one sure character in the inner circle is Salman’s son Muhammad, who has headed the crown prince’s court and now been made minister of defense. Only in his 30s, Muhammad bin Salman has yet to demonstrate a clear skill set, but his ambition is gigantic. Other sons include Abdulaziz, the perpetual assistant oil minister; Sultan, the astronaut who shared a space shuttle with a female American crew member, Shannon Lucid, despite strict Saudi notions of gender separation, and is now in charge of tourism and antiquities; and Faisal, the governor of Medina province whose Oxford doctorate discussed power politics in the Persian Gulf.

The other key question is whether King Abdullah’s death will precipitate significant changes in Saudi policy. While Abdullah hated Syrian President Bashar al-Assad, Salman’s camp may approach the Syrian civil war in a less visceral way and be more amenable to diplomatic compromise. But the sons of Salman probably share the House of Saud’s profound suspicion of Iran and ISIS. Domestically—on issues ranging from the role of women in society to the powers of the Consultative Council and municipal councils—will Salman be more “reformist” than Abdullah was? Perhaps so once Salman has consolidated power, though his camp will probably steer a more cautious course until it has had time to judge what the largely conservative Saudi populace wants.

What international observers most want, meanwhile, is to know what Saudi Arabia will do next regarding the price of oil. This is the policy arena where Saudi thinking is most likely to change under Salman, though less as a result of a strategic shift than of frustration that the current policy—accepting falling oil prices in an effort to preserve the country’s global market share—is not working. The kingdom is currently keeping its head above water while other oil-producing nations—and rivals such as Russia, Iran, and even U.S. shale-oil producers—struggle, hoping that the price of oil recovers or that U.S. shale-oil production slumps. Abdulaziz bin Salman, who has spent his oil-ministry career tolerating his own marginalization by the oil minister Ali al-Naimi, may play an influential role in steering Saudi oil policy in a new direction.

The House of Saud often seems like an old-fashioned family business, but the weakness of such a corporate structure is that the most senior member rather than the most competent gets to be chairman. (In Saudi Arabia, it will always be a man.) This works well enough as a business model if the commercial environment changes slowly. But when there are new competitive pressures (ISIS, Iran, Yemen) and the market price of your product (oil) has suddenly halved, you are in danger of becoming a classic business case study, a proud dynasty that failed to change with the times. The greatest strength of the Saudi royals is their outward display of unity. Yet it is also a weakness. Salman is a transitional leader. Along with his half brother, Muqrin, he is the bridge to the next generation. But if the throne eventually passes to Muhammad bin Nayef, where does it go from there? To his sons? His brothers? Saudi succession is a work in progress, at just the moment when the kingdom faces an array of grave threats and distractions.