When Saudi Arabia’s King Salman ascended to the throne this past January, he took the reins of power at perhaps the most crucial period of time since his father, King Abdulaziz, founded the kingdom some 83 years earlier.

With Yemen boiling over to the south, the ISIL threatening to the north, Iran seemingly encircling the kingdom, and the ever-present social, economic and political issues on its domestic front, Saudi Arabia needed a strong and decisive leader with a clear, long-term vision.

Few doubted he was up to the task then, and given his unexpected shake-up of several key policy positions earlier this week, even fewer should doubt him now.

Three of those moves stand out as truly remarkable, both for what they say about King Salman’s vision and resoluteness, as well as for what they could mean for Saudi Arabia’s domestic and foreign policy landscape – now and perhaps for decades to come.

Three bold moves

By replacing Crown Prince Muqrin bin Abdulaziz, his half-brother and the youngest son of King Abdulaziz, with Interior Minister Prince Mohammed bin Nayef, and then appointing his own son, Defence Minister Prince Mohammed bin Salman as Deputy Crown Prince, King Salman has opened the line of succession to a new and much younger generation – the grandsons of King Abdulaziz.

Equally bold, was the replacement of Prince Saud al-Faisal, who served as Saudi Arabia’s foreign minister for nearly four decades, with Adel al-Jubeir – currently the kingdom’s ambassador to the United States, and only the second foreign minister not from the royal family. But who are these new leaders, and why do their appointments really matter?

Since first being named assistant interior minister for security affairs in 1999 and then continuing on with his security portfolio after being named minister of interior in 2012, Prince Mohammed bin Nayef has proven ruthless in taking on al-Qaeda and other extremist elements within the kingdom, particularly during their peak years from 2003-2005.

More recently, he has taken a leading role in Saudi Arabia’s efforts to counter Iranian influence in Yemen and the Islamic State of Iraq and the Levant. He is also King Salman’s point man on how the kingdom will manage Iran’s growing influence elsewhere in the region.

At 55 years of age, Crown Prince bin Nayef is highly regarded within the kingdom, the region and the West, especially within European and US counterterrorism and national security circles – a key point that certainly figured into King Salman’s decision to make the change. He has a well-earned reputation as a smart, pragmatic, decisive and politically astute leader. He’s even considered to be media savvy, a characteristic not usually associated with the royal family.

Overwhelming support

On the other hand, Deputy Crown Prince Mohammed bin Salman – only in his 30s – is still largely unknown and untested. He was the youngest minister of defence in the world when appointed to that post just three months ago. However, when the Saudi-led coalition began their military campaign against the Houthi rebels in Yemen last month, Prince Mohammed bin Salman was given primary responsibility for leading it.

Right now, the Yemen campaign still has overwhelming support within the kingdom and among Sunni coalition partners for its hardline stance against the Houthis – and by extension, Iran. However, with its outcome still uncertain, support can quickly diminish if it drags on indefinitely. Regardless of how the Yemen campaign turns out, it will serve as the initial baseline for Prince Mohammed bin Salman’s reputation, which, given his young age, he will undoubtedly have years more to build upon.

Perhaps a more significant yardstick of his leadership abilities, and area in which Prince Mohammed bin Salman is sure to be closely scrutinised over the long term, is his position as chairman of the Committee for Economic and Development Affairs – which is the key to the kingdom’s future prosperity and economic viability.

But for now at least, he – along with Crown Prince bin Nayef – will be Saudi Arabia’s two most dominant players from a national security perspective. And given the level of those threats, both internally and externally, it will be paramount that they remain close allies. Fortunately for the kingdom, there’s nothing to indicate that won’t happen.

Foreign Minister Adel al-Jubeir – at 53 years of age – is also representative of a new, younger generation of Western educated leaders in the kingdom.

Younger generation

Fluent in both German and English, he brings a global perspective on economics and international affairs to the foreign ministry and is considered the consummate professional and diplomat.

Receiving an appointment to the Saudi Diplomatic Service in 1987, he served primarily in the United States, most recently as ambassador since 2007. Like Crown Prince bin Nayef, Jubeir is comfortable in front of the media – a rarity for senior Saudi ministers.

With Saudi Arabia currently engaged militarily in two conflicts – one in Iraq and Syria to its north and the other in Yemen to its south – the task of maintaining the kingdom’s crucial leadership role in the region, as well as strengthening its relationships with key regional and Western allies, will fall largely on the shoulders of the foreign minister.

By elevating Crown Prince Mohammed bin Nayef and Deputy Crown Prince Mohammed bin Salman to their new posts, King Salman has set in motion a line of succession that – if kept in place – could provide the continuity and leadership necessary for the kingdom’s long term security and prosperity, a point that is not lost by Saudi Arabia’s friends and foes alike.

And with Foreign Minister Jubeir, he has a pragmatic and well-respected diplomat with the skills necessary to help propel Saudi Arabia to a much greater role in regional and global geopolitical affairs for many years to come. Three bold moves by King Salman.

By Martin Reardon who 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.