King Salman’s policy changes are the efforts of an absolute monarch to re-establish his country’s clout in a region torn apart by civil wars, where weak states are contending with jihadists and rising sectarianism — as well as American reluctance to get too deeply involved.

The new policies are driven by a desire to confront the rising influence of Iran, the kingdom’s Shiite adversary, at a time when a potential deal on Iran’s nuclear program could improve Tehran’s fortunes. They also reflect a resurgence of the pre-Arab Spring model of governance that emphasized centralization of power and a security-first approach to preserving authority and stability.

King Salman has made no gestures toward social or political liberalization in a country where women cannot drive and dissenting views can lead to prison.

In January, he replaced the head of the religious police who was seen as trying to curb excesses of the force. He has also dismissed the deputy education minister, the only woman in such a high-level cabinet post, and appointed as a royal adviser a cleric whom King Abdullah had dismissed for criticizing the country’s first coed university.

But his focus appears to be security, a reaction to the growing influence of Iran and the rise of extremist groups like the Islamic State, also known as ISIS or ISIL. In addition to leading an air campaign in Yemen, he has promoted security-minded officials, naming his nephew Prince Mohammed bin Nayef, 55, who as interior minister has led the kingdom’s counterterrorism efforts, crown prince.

Fueling the change is frustration with the United States, long considered the kingdom’s closest Western ally and guarantor of its security. Saudis accuse the Obama administration of neglecting its Arab allies while prioritizing rapprochement with Iran.

In increasing the kingdom’s regional role, King Salman risks escalating the conflict with Iran, fueling further instability. And his support for Islamists could end up empowering extremists, just as Saudi support for the Afghan jihad decades ago helped create Al Qaeda.