Prime minister Keir Starmer has courted controversy by deciding not to go ahead with the appointment of Gwyn Jenkins as the UK government’s national security adviser, the most senior position in national security.

Asked during a speech in Downing Street to comment on the move, Starmer refused, saying only that he was moving ahead with the appointment process.

Jenkins, formerly the vice-chief of the UK armed forces, was originally appointed by former prime minister Rishi Sunak in April 2024.

Starmer’s decision to replace him with someone else has been criticised because he appears to be looking to appoint someone more politically loyal.

Jenkins was Sunak’s pick but he certainly has extensive experience and went through an exhaustive interview process to get the job. It might therefore seem as though Starmer is playing politics with an important government position.

However, while these concerns should be noted, they miss the crucial purpose of the position of national security adviser. The person in this role needs to have a strong personal relationship with the prime minister. So it’s actually understandable that Starmer would seek a different person.

It potentially only appears strange because he is the first Labour prime minister to appoint someone to the job. This is the first time the government has changed hands since the role of national security adviser was created in 2010 – which explains why it has never been a problem before.

What the national security adviser does

The position of national security adviser was created in 2010 under the government of David Cameron. This was when the National Security Council (NSC) was first established in order to formalise the government’s security decisions.

The NSC brings cabinet ministers together with senior intelligence officials in a single decision-making forum with the prime minister. The idea was to move away from the “sofa government” style of Tony Blair, who had a tendency to make important decisions in informal settings with only his closest allies. Among other responsibilities, the national security adviser coordinates the work of the NSC.

Having a dedicated national security adviser also streamlines the process of advising the prime minister on security. That means both serving as the prime minister’s day-to-day contact on issues of national security but also bringing new issues to their attention.

The national security adviser sets the agenda for the NSC, sits next to the prime minister in the NSC, and coordinates the flow of information and advice to NSC members.

The NSC has dealt with crises from the military deployments in Afghanistan to the Salisbury poisonings and terrorist attacks. In many of these crises, information would be limited and events would still have been unfolding as decisions made.

During terrorist attacks in London and Manchester in 2017, for example, it would have been difficult to know whether these were isolated incidents or part of a wider campaign of attacks. For a prime minister, developing trust quickly, or being able to choose someone who they already trust will necessarily help them address these unpredictable events during a crisis.

As such, the relationship between prime minister and national security adviser is a close one. It’s therefore only natural that Starmer wants someone new of his own choosing. Jenkins was appointed by Sunak, who presumably judged that he could perform these responsibilities in the way Sunak wanted. Starmer may not necessarily want the same kind of relationship with his national security adviser.

At times of high stress and high intensity, close relationships between advisers make for better decisions. For a prime minister who is new to office, this is even more important.

Blair sought to achieve this by having Downing Street chief of staff Jonathan Powell and Alastair Campbell in the room during crisis decision-making. Boris Johnson and his national security adviser Mark Sedwill reportedly did not get along, and as the COVID inquiry has revealed, this affected decision-making culture in Number 10 during the pandemic.

A question of trust

Critics of the decision to replace Jenkins are missing the importance of this personal relationship. His experience is, of course, important to the role. But it is not the only aspect of the job. Whether Jenkins was appointed properly or not doesn’t mean he would have the right relationship with Starmer on a personal level.

During the intervention in Libya in 2011, the National Security Council met over 60 times in six months. This intensity of meetings during an ongoing crisis highlights the importance of a good working relationship.

Jenkins, meanwhile, has also attracted controversy of his own, which may have made Starmer reluctant to keep him in position. The BBC reported in 2023 that Jenkins received reports that SAS (UK Special Forces) personnel had claimed to have killed detainees, and rather than passing this information on to military police for investigation, he locked the reports in a classified safe. No one has been convicted of any killings but a public inquiry into the matter is ongoing and Jenkins has never commented on the allegations.

While the replacement of the national security adviser may seem controversial, the importance of the position means that effective relationships are crucial. It’s right that the first Labour prime minister in over a decade should be able to replace a man who served predecessors from another party if he sees fit to do so.