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While there are many pressing domestic challenges to address in both the short and long term, particularly in regards to needed social and political reforms, it is the national security issues from external threats to the kingdom that will demand King Salman's undivided attention first.

With his ascension to the throne last week, Saudi Arabia's King Salman has taken the reins of power at what may be the most crucial time in the country's modern history. Fortunately for both the kingdom and the region at large, he is widely regarded as a pragmatic and decisive leader who is wholly up to the task at hand.

He is also considered a cautious reformer, unlikely to change direction too quickly with regard to Saudi Arabia's domestic and foreign policies. With more than five decades in senior government positions, including governor of Riyadh, deputy prime minister, minister of defence and crown prince, he is well versed in the issues - both internal and external - most affecting the kingdom's security and future.

While there are many pressing domestic challenges to address in both the short and long term, particularly in regards to needed social and political reforms, it is the national security issues from external threats to the kingdom that will demand King Salman's undivided attention first.

Three stand out as the most immediate.

Yemen to the south

King Salman's most urgent national security issue right now is the crisis in Yemen. Two issues there in particular, cause Saudi leaders to lose sleep at night. First, since their sudden and unexpected rise to power last September, Houthi rebels, who are from the Shia branch of Islam, have largely succeeded in marginalising Yemen's president, causing gridlock in what was already being labelled a dysfunctional government in danger of collapse.

In fact, last week, they forced the resignations of not only the president, but his cabinet and prime minister as well. As far as the Saudis are concerned, the Houthi takeover was in large part orchestrated by Iran as part of their strategy to close in on the Kingdom - but more on that later.  

Profile: Salman bin Abdulaziz al-Saud

King Salman is also faced with an ever-increasing threat from al-Qaeda in the Arabian Peninsula (AQAP), which uses Yemen's al-Marib province as their sanctuary and base of operations.

AQAP is considered by many counterterrorism specialists to be the most capable and dangerous terrorist organisation in the world, and has proven adept over the years at planning and successfully carrying out sophisticated terrorists attacks outside of Yemen.

For years, Saudi Arabia has been hit particularly hard by AQAP, which takes advantage of the kingdom's porous border with Yemen in carrying out those attacks.

ISIL to the north

To Saudi Arabia's north, they share another porous land border with Iraq that stretches nearly 800km. In recent years, the Saudis were most concerned with having an Iraqi government closely aligned with Iran along that border. However, since the Islamic State of Iraq and the Levant (ISIL) swept into western Iraq last June, they have supplanted the Iranian-allied government in Baghdad as the Saudi's biggest concern there - at least for now.

As a self declared caliphate, it would make sense for ISIL or their sympathisers to challenge King Salman as the Custodian of the Two Holy Mosques in Mecca and Medina. While it's not likely ISIL could ever succeed in making an all out assault against the kingdom as they did in Iraq and Syria, there have already been a number of border clashes between them and the Saudi military.

Three weeks ago, Saudi forces engaged suspected ISIL infiltrators along the border as they attempted to penetrate through a perimeter fence. Four fighters and three Saudi soldiers, including their commander, were killed in the firefight. Remember, too, that close to 3,000 of the ISIL fighters in Iraq and Syria are Saudis themselves.

Just as disconcerting, most of the ISIL suicide bombers are also Saudis. If and when those fighters return home, King Salman's government is going to have to deal with them as a domestic issue.

Saudi Arabia also plays a key leadership role in the coalition aligned against ISIL. As that fight goes on over the course of months or years, their continued commitment to the strategy and status as an Arab power will become even more crucial.

Iran closing in

It's no secret that Saudi Arabia and Iran are locked in a struggle for power and influence in the region, and right now Iran appears to have the upper hand. Besides Yemen and Iraq, Iran is also firmly entrenched in Syria and Lebanon, extending their sphere of influence across a wide swath of the Middle East to the Mediterranean Sea and Gulf of Aden.

In Saudi Arabia's eyes, Iran is also responsible for sowing unrest among the Shia communities in Bahrain and their own eastern provinces. For Saudi Arabia, Iran's nuclear ambitions are an existential threat not only to them, but also to the entire Sunni Arab world that must be stopped.

In Saudi Arabia's eyes, Iran is also responsible for sowing unrest among the Shia communities in Bahrain and their own eastern provinces. For Saudi Arabia, Iran's nuclear ambitions are an existential threat not only to them, but also to the entire Sunni Arab world that must be stopped.

Complicating matters for King Salman in that regard is the fact that Saudi Arabia's closest ally, the United States, is not only in direct negotiations with Iran over their nuclear programme, but is also working diligently to restore the relationship they had with Tehran prior to the 1979 revolution. That, more than anything else will give King Salman cause for concern.

Managing the situation

Soon after he ascended to the throne, King Salman assured the Saudi people and the world that he would maintain the same policies as his predecessor, and in a region that faces unprecedented turmoil, that pledge of continuity is important.

For King Salman, continuity will mean preserving Saudi Arabia's leadership role in the region, maintaining open lines of communication with friend and foe alike, keeping a wary eye on his opponents' every move and looking for opportunities to exploit.

In short, managing the situation by containing the threat.  

Yemen, ISIL and Iran each pose their own unique set of challenges, but King Salman's assurances of continuity give some indication as to how he will manage them. In Yemen, look for the Saudis to focus on a long-term approach to stabilise the government and lessen Houthi influence.

A more functional government in Yemen will also be in a better position to address the AQAP threat. In the near term, the Saudis will bolster security along their southern border in an effort to contain AQAP. In the fight against ISIL, the Saudis will strengthen security along the Iraq border, while at the same time maintain their strong and indispensable leadership role within the coalition.

With Iran and those countries in their sphere of influence, King Salman is likely to continue Saudi Arabia's long-standing policy of containment, while waiting and watching for opportunities to exploit.

It would be an understatement to say King Salman is facing what may potentially be the biggest threat from external sources in the kingdom's history. Each requires the skills of a calculating leader who thinks strategically and in the long term. 

With King Salman, Saudi Arabia may very well have that leader. The next few months will tell.

Martin Reardon is a senior vice president with The Soufan Group, a New York-based strategic security and intelligence consultancy, and senior director of Qatar International Academy for Security Studies. He is a 21-year veteran of the FBI, and specialised in counterterrorism operations.

The views expressed in this article are the author's own and do not necessarily reflect Al Jazeera's editorial policy.

Source: Al Jazeera