Riyadh: Former Crown Prince Nayef, who died on Saturday, oversaw security for 37 years and built a formidable apparatus that crushed Al Qaida inside the kingdom and remains a vital element of the global struggle to foil militants. His tough legacy, involving thousands of arrests of suspected militants, an intelligence network that infiltrated Islamist cells, and an intolerant approach to political dissenters. The new crown prince will eventually succeed to power having to deal with significant domestic and external challenges, including a substantial security file. Prince Salman inherits an ongoing proxy war between Riyadh and Tehran as well as its southern neighbours problems with Al Qaida. And while Saudi Arabia emerged unscathed from last year’s Arab Spring, the turmoil destabilised neighbouring Yemen and Bahrain and has brought ally Egypt to the brink of government by the Muslim Brotherhood, with which Riyadh has an uneasy relationship.

The kingdom’s new heir apparent will also face a number of other challenges including long-term joblessness.

“The thing that Salman’s going to have to do is try and get some influence over some of the religious establishment in the country,” said Michael Stephens, researcher at the Qatar-based Royal United Services Institute.

“He’s going to have to start commenting on regional security issues as well as foreign policy initiatives.”

Any incoming king is seen as likely to stick with Saudi Arabia’s moderate oil pricing policy and to maintain its close alliances with the United States and Sunni Muslim Arab states.

Saudi Arabia’s line of succession does not pass from father to eldest son but along a line of brothers born to the kingdom’s founder Abdul Aziz Bin Saud, who died in 1953.

Around 20 brothers still survive but only a few of these might be considered contenders to rule the world’s biggest oil exporter.

Salman was long been seen as the next most obvious choice to succeed King Abdullah. “We have seen Abdullah make pretty hard-headed decisions, unsentimental decisions, about family jobs. He chose Nayef over eight living princes. He has shown that age and seniority give way to competence and appetite for the job,” said Robert Lacey, author of Inside the Kingdom.