Deutsche Welle: Ban Ki-moon's second term as secretary-general of the United Nations ends this year. How is the new UN secretary-general elected?

Mats Berdal: The secretary-general of the United Nations is, according to the UN charter, appointed by the General Assembly upon the recommendation of the Security Council.

And that process is heating up. Governments have suggested possible candidates, and then an attempt is made among the council members to agree on an appropriate candidate through various soundings, secret discussions and straw polls where you see whether or not there is enough support for a candidate.

This time that is perhaps more intensely political than it has been for a long time because there are deep divisions within the Security Council over issues of policy. The Russians and the Western powers have been divided over the Middle East, and over Russian actions in Crimea, and therefore there is a fear that they might not be able to end up with candidate who deserves to be there purely on his merits. It might be a comproise candidate.

The current Secretary-General Ban Ki-moon and the UN itself have been accused of being too weak and ineffective in various crises. For example, when it comes to the war in Syria. But, as you said, the US and Russia are on very different sides of that conflict, so it seems unlikely they would agree on a candidate that the other side favors.

The secretary-general is first of all basically a chief executive officer. But, he's also potentially someone who can take a political role and bring issues to the attention of the Security Council and play an active role, for example, in suggesting that peace operations be initiated. The fundamental fact is that the UN is an intergovernmental organization, it is not a supranational organization, and the secretary-general himself is really no more than a primus inter pares. He can cajole, he can encourage, and he can nudge member states to take certain actions, but he cannot force or order them to take actions. So the geopolitical realities of world politics determine the space within which the secretary-general can operate.

Does that mean it would be hypocritical to accuse a person who is in that post of not being outspoken enough?

There's a balance to be struck here - assessing what a secretary-general can realistically achieve given the state of international relations, against what his constraints are. A good example is to go back to Dag Hammarskjoeld. He was secretary-general between 1953 and 1961 at a time when Cold War tensions were very high. And he famously said that he recognized that there are deep divisions between the East and West, but his role, as secretary-general, was to find possibilities for action on the part of the United Nations in a world that is split and divided.

If you look at the role in that way, the secretary-general does have some scope for action. And this is where some of the criticism against Ban Ki-moon has been directed, in the sense that they've accused him of not being proactive enough in relation to certain conflict, that he has perhaps been too subservient to the interests of member states. The secretary-general is often described as a sort of secular pope, meaning that he also has an important role in drawing attention to conflicts, to the responsibilities that member states have in addressing human rights violations and so on. And that high-profile role is an important one, which perhaps Kofi Annan cultivated more than anyone. And I think the new secretary-general would try to assume a greater role in mediating in conflict.

That is of course very difficult in conflicts where the interests of member states particularly the permanent five in security council are deeply at odds with one another, like in Syria. But there are many conflicts that are crying out for attention, South Sudan and Congo being two cases in point.

Would a woman candidate - that many countries have pushed for - be a better person to fill that role?

We have yet to see a female secretary-general. One of those now rumored to be a strong candidate is Bulgaria's Kristalina Georgieva. This also reflects not just the gender issue, but there's also a sense that we now had someone from Asia, and some people argue that it's now the turn of Eastern Europe, and therefore that combination might be possible. But in terms of those that are the frontrunners, there's Georgieva and also Antonio Guterres from Portugal, who used to run the UNHCR and did a very good job there.

Who do you think is going to win? Do you have any guess?

It is extremely difficult to predict because it comes down to the politics, and given that the Russians and the Americans are so much at odds over other issues and they will have to agree on an acceptable candidate.

What would be the main characteristics that a candidate needs to be successful as the next secretary-general?

I think it is a very difficult balance to strike between working with member states, and particularly the Security Council, and at the same time retaining independence and speaking for the membership as a whole. It is a very very difficult job, but it is also still a very important job - not least because of this norm-setting function it has, because in a way it's supposed to represent the conscience of the world.

The next straw poll in the security council is set to take place on September 26th.

Mats Berdal is a Professor of Security and Development at the Department of War, King's College London. He also directs the Conflict, Security and Development Research Group there. He is a leading international scholar on conflict and post-conflict situations. He was also director of Studies at London's International Institute for Strategic Studies (IISS) from 2000 and 2003.

This interview was conducted by Anke Rasper.