I was the first legal adviser to be appointed from outside the Diplomatic Service. As an initial matter, therefore, I had to familiarise myself with the workings of the office. Beyond that, I gave a great deal of thought to whether I should be adapting my working style to that of the office or should be trying to bring to the post something of a different approach. I opted for a hands-on advisory role, working to ensure that I and the legal team were closely engaged on policy discussions with a view to ensuring that law shaped those discussions from the earliest stages.

What differences did you observe about our legal service compared to that of other countries?

Size! We are a considerably smaller legal team than most other natural comparators, having about a sixth of the number of lawyers of the US State Department and being smaller than many of our European counterparts. Another aspect is the non-political role of the FCO legal adviser by contrast, for example, to that of the State Department legal adviser, which is a Senate-confirmed position. This had interesting implications, as my US counterparts – successively, John Bellinger and Harold Koh – had much more public-facing roles, including on issues on which it may have been useful for the UK to have engaged publicly.

What do we in the UK do well?

Law! The FCO legal team is a specialist cadre of lawyers that, with rare exceptions, remain in legal roles throughout their Foreign Office careers. This is a contrast with many other foreign ministry legal departments, which are composed of diplomats who rotate in and out of the legal team. One consequence of the UK system is that the legal team really is highly expert, and a considerable repository of institutional knowledge and thematic expertise.

Apart from giving advice, how does the legal team at the FCO add value?

There is a legal dimension to most foreign policy issues. The role of legal advisers is not therefore simply to provide advice on this or that aspect of formulated policy but also to help in shaping that policy from the outset to secure the objective in a manner that is consistent with our laws and values. The legal role also goes more broadly, including a strong representational function and the maintenance of contacts and channels of communication with counterparts in foreign ministry legal teams around the world, in states, international organisations and the non-governmental community.

Was your background as a barrister a good training for the FCO job?

I hope so. Quite apart from the growing volume of challenging litigation during my tenure, the experience that one develops at the Bar in marshalling argument and advancing a case was important, both in internal discussions and externally. On the downside, I came to the post with only limited managerial experience and aptitude.

Your stint must have changed the way you will approach and shape your practice now?

Undoubtedly! Although my pre-FCO practice was heavily focused on government work, I now have a much deeper appreciation of the challenges faced by government and by those advising them. Some of the big challenges of government are to be strategic in a highly pressurised day-to-day environment and learning how to operationalise ideas. Law has both a strategic and an operational dimension. I am much more aware now of the challenges of managing these two roles within the framework of government.

What advice would you give to young lawyers interested in international law?

International law is a vocation, not a job. My advice to those starting out would be to have patience; to be aware that all the little steps that you take to develop your interest in the subject will make you a better, and more rounded, lawyer in due course; to see advantage in a wide-ranging expertise across the discipline and not to rush too quickly towards narrow specialisation. Up until the point of my appointment to the FCO, I divided my time between academia and the Bar. Teaching is a wonderful means of maintaining your knowledge base across areas that may not always be coming across your desk as a practitioner.

As a former investment banker, how would you say decision-making compares between the worlds of investment banking and, say, the military?

I would be cautious about speaking for either of these communities. My experience of investment banking was of an enormously creative, versatile and energetic community in the mid-late 1980s. They had, and I imagine still have, an “anything is possible” attitude. This can be very positive and enabling. As with all endeavours, though, one must ask oneself not simply “is it possible?” and “is it legal?” but also “is it wise?”. This injunction to enquire into the wisdom of action applies also in government and raises questions not simply about the wisdom of the policy that is under discussion but also about the decision-making structures, and whether these are conducive to the asking of the right strategic questions, rather than simply the effective prosecution of

Sir Daniel Bethlehem QC KCMG was interviewed by Matthew Lawson and Stephen Turvey of LPA Legal Recruitment