The departure of Boris Johnson as Foreign Secretary marks the end of the second occasion in recent years where a would-be ‘prime minister in waiting’, and direct rival, has occupied the Foreign Office.

Johnson’s tenure, – often characterised as turbulent and steeped in controversy — raised many to question his suitability in the role. However, whatever his personal shortcomings one should consider whether the fault lies instead in the flawed logic of appointing a political rival to the top diplomatic role in government. After all, political rivals rarely make good foreign secretaries—or for that matter good foreign policy.

In both 2007 and 2016 new premiers, untested by the electorate, and crowned only by their party, made the decision to despatch their leadership rivals to the Foreign Office. The logic behind the appointments was considered at the time to be sound party management: as the Foreign Office is not only considered one of the greatest offices of state but the demands of frequent travel abroad often leave its occupant isolated from domestic politics. Similarly, the regular summits and numerous diplomatic engagements also limit a foreign secretary’s ability to engage in parliamentary party politics.

When selecting a foreign secretary in contemporary British politics, prime ministers must also consider their own increased role in foreign policy. Long gone are the days where a foreign secretary could be unchained and free to craft the nation’s foreign policy. Instead, with the advancement of mass communications, regular diplomatic summits, and the globalisation of domestic politics, today’s political terrain has all but ensured that the Prime Minister is firmly in the driving seat when it comes to the formulation of foreign policy.

However, the increased prime ministerial role in foreign policy did not stop either Gordon Brown or Theresa May taking further precautions to limit the influence of their new foreign secretaries. Brown signalled early on that David Miliband would not have a free hand at the Foreign Office by appointing the former Deputy-UN General Secretary Lord Malloch-Brown as a Foreign Office Minister to effectively watch over him. Over the next three years communication between the Prime Minister and the Foreign Office largely flowed through Malloch-Brown. It was Malloch-Brown—and not Miliband—who held regular late-night phone calls with the Prime Minister during the worst foreign policy crises.

May on the other hand used the opportunity presented by Brexit to weaken the institutional power of the Foreign Office through the creation of the Department for International Trade and the new Department for Exiting the European Union.  This effectively deprived Boris Johnson of involvement in both the Brexit negotiations and the negotiations around the signing of new free trade agreements, much to his frustration.

However, a weakened Foreign Office, by its own nature, undermines a prime minister in their party handling, because having a foreign secretary who is seen to be a direct rival and a potential successor inevitably becomes a source of distraction and disunity. Rather than focusing on the day to day running of British foreign policy, both Miliband and Johnson found themselves embroiled in party plots and constantly floated by the press as potential replacements for unpopular prime ministers. This in turn led to even further mistrust between No.10 and their respective Foreign Offices and in some instances, open disagreement on key policy.

One only needs to look at the press coverage of Brexit over the last two years, where quotes and comments from Boris Johnson criticising and contradicting the Prime Minister’s policy on Brexit became an increasingly common fixture.  Similarly, while less frequent, Miliband did at times openly contradict Brown, particularly over the Government’s position on the EU Lisbon Treaty.  Both relationships fed into the UK’s continued fractured foreign policy when it comes to the European Union.

Perhaps it is inevitable that the occupant of the Foreign Office would always be seen as a potential rival given the visibility of the role on the world stage.  However, in the case of both Brown and May they appeared to deliberately appoint key rivals to the top diplomatic post to try to isolate them. However, for both Brown and May this appears to have had the opposite effect where the weaknesses of their premierships amplified the rivalries and disagreements in their relationships with both foreign office incumbents and did little to further British foreign policy priorities.

Looking objectively at British prime ministers and their foreign secretaries over the last fifty years the most capable foreign secretaries have often been individuals who were not necessarily considered direct political rivals. In the case of Lord Alec Douglas-Home and William Hague this was because the electorate had already rejected them as previous party leaders. Lord Carrington’s hereditary peerage all but eliminated him for consideration as a potential prime minister, smoothing the way for him to have a close working relationship with Margaret Thatcher. Even when James Callaghan entered the Foreign Office he considered himself far too old to ascend to the premiership, allowing him instead to focus on the diplomatic crises of the day.

It is too early to tell what kind of foreign secretary Jeremy Hunt will be, whether he will have improved relations with the Prime Minister or what kind of an impact he will have on – UK foreign policy. One thing, though is certain: his appointment rests on the fact that Theresa May does not consider him a political rival and instead as someone who she might be able to work with towards building a more coherent foreign policy.