In Conversation with Wiebke Rückert

Dr. Rückert, thank you very much for accepting this invitation from the Völkerrechtsblog, which will form part of a Völkerrechtsblog series: The Person behind the Practitioner.

Thank you very much for having me!

To frame the following interview, it would benefit our readers to know a bit more about your extensive career in international law.

Wiebke Rückert is the Director for Public International Law at the German Federal Foreign Office (Auswärtiges Amt). In this role, she has represented Germany before the International Court of Justice (ICJ) and in numerous international negotiations. As a German career diplomat, she was previously Head of the Division for Human Rights, Deputy Head of the Division for Public International Law and, on one of her first postings, member of the Federal Foreign Office task force for the establishment of the International Criminal Court. She has also been Practitioner-in-Residence with the Berlin-based research group “The International Rule of Law – Rise or Decline?” and a Judicial Fellow at the ICJ. Wiebke Rückert obtained a doctorate in international and constitutional law from Humboldt-Universität in Berlin and an LL.M. in International Legal Studies from New York University.

Dr. Rückert, you have experienced the world of international law from different angles – diplomacy, academia, international courts. How would you describe the relationship of law and diplomacy in your work and in international law in general?

Law and diplomacy are deeply intertwined in my work – and I believe this is equally true with regard to international law more broadly. Diplomats who are serving as legal advisers advise their governments internally on what international law says and how it applies. Externally, diplomats explain and defend the positions taken by their government, including on questions of international law. They also help shape the law itself: they negotiate treaties and contribute to the development of new norms when needed. Sometimes diplomats even publish academic work. At the same time, academic publications are regularly taken into consideration in diplomatic practice. Governments often seek and rely on academic advice for complex legal questions. I see enormous value in this ongoing dialogue between academic international lawyers and those applying the law in practice. It enriches both sides.

Diplomats and other governmental representatives are perhaps the principal ‘law-makers’ in international law. They draft treaties and partake in the creation of customary law. Still, the role and processes of this ‘International Legal Policy’ are underexplored in legal scholarship. In your opinion, what are the key elements of Germany’s international legal policy, and how would you describe Germany’s approach towards the international legal order?

Germany’s approach to the international legal order is shaped by our history and the responsibility that history carries. Our Constitution, the Basic Law of 1949 (Grundgesetz) envisioned the German state being firmly anchored in the international community, and German state authority being geared, as a matter of policy, towards international cooperation. The Basic Law is “international-law-friendly”. Our Federal Constitutional Court just confirmed this in its recent ruling of 15 July 2025. This Völkerrechtsfreundlichkeit (literally translating to “friendliness towards international law”) stems from several constitutional norms. It means that ius cogens rules, including core norms on human rights, the protection of the environment or of international humanitarian law are directly part of our constitutional legal order. German state organs have a general obligation to protect these norms. Germany’s international legal policy rests on the conviction that the international legal order should be sustained, protected, and enhanced, if need be. We believe that international law is in our national interest, but also in the shared interest of all countries and therefore in the interest of the international community as a whole.

Why is that so? First, because international law ensures that all States, big or small, can participate equally in international relations. In a world order dominated by power alone, only the strongest and most ruthless actors will win. International law offers a fundamentally different vision: that of sovereign equality of states.

Second, international law forms the guardrails of foreign policy action. It acts as a check on arbitrary power. The prohibition of the use of force enshrined in the Charter of the United Nations is paramount in this regard. It embodies the aspiration and the promise that countries can deal with one another without the use of violence.

Third, law creates peace. It provides countries with avenues to resolve conflicts peacefully. The increasing number of cases before international courts shows that ever more countries are making use of the options for peaceful settlement of conflicts that international law offers. That is a positive trend.

Opinio iuris is a key element for the creation of customary international law. Does this risk of contributing to a change of the law influence your work? I imagine you have to be quite careful when every statement you draft might shape customary law.

Yes, we are very conscious of the fact that what we say – especially in formal settings – can contribute to shaping an understanding of customary international law. This is particularly true when States submit views to the International Law Commission: those positions are drafted with great care. The same applies to statements before international courts or treaty bodies. But of course, not all government statements convey a legal position, many statements are purely political. Still, we always keep in mind that our words can have legal ramifications.

How do you view the relationship of international legal practice and scholarship? Do you draw on scholarly publications in your work?

To be honest, our busy daily lives don’t always leave much time for reading academic work in depth. But that doesn’t mean that it doesn’t play an important role. In our Ministry, we are known for having our legal texts and key reference material always at hand to be able to refer to them. When we give legal advice, we absolutely consider the scholarly debate. The library at the Federal Foreign Office has excellent resources, so no publication is ever out of quick reach. In my view practice and scholarship are two sides of the same coin: practice gives rise to new questions, it fuels scholarship. Scholarship in turn helps refine – or challenge – the answers. It gives practitioners new arguments to consider, or reason to revise views.

Do you have any advice for academics to improve the practical relevance of their work?

If you are an academic who wants to speak to practice, the best thing you can do is to tackle questions that are of acute practical relevance. Timing also matters. Classic, timeless debates will always find readers among practitioners. When new problems arise, however, publications that appear quickly and within a short time-frame are best placed to shape practitioners’ legal thinking. That is where blog posts and other short formats shine: They help to shape the conversation as it unfolds. Let me put it this way: Völkerrechtsblog matters!

That is very encouraging to hear! I hope you and your colleagues around the world will continue to find articles on Völkerrechtsblog helpful for your work.

There is a lot of talk about great-power competition and ‘multi-polar order’ on the one hand, and the special role of small states in international law on the other. Germany, however, is probably a good example of a ‘middle power’. What role do middle powers have in contemporary international law? How can they leverage their influence?

The definitions are likely contested, but I see what you mean. Germany is often described as a “middle power”. Such powers cannot simply exert their influence unilaterally, like great powers might sometimes do. They rely on alliances and partnerships, seek cooperation. They have a strong natural interest in a stable international legal order. I believe that is why middle powers are also often among the most vocal supporters of international law.

They can leverage their influence, especially through regional groupings, by building coalitions and advancing ideas collectively.

After these more general questions, I would like to ask more about your role as a legal adviser of the German Foreign Office. How do you view this role? Do you see yourself primarily as a lawyer or as a diplomat?

In Germany, all diplomats rotate from post to post. That includes diplomats working in legal roles. We do not have a separate legal service. Our legal directorate-general is staffed by diplomats with legal training who are posted to it for a few years at a time. Many of us return to the legal directorate several times, like I did. Recently, very few positions have been opened up for “non-rotational” lawyers. The colleagues in these new positions might see things differently in the future, and consider themselves primarily lawyers. As far as I am concerned, however, the answer is clear: I am first and foremost a diplomat, but a lawyer by training and expertise. Some call us lawyer-diplomats, maybe that captures it well.

What is your favorite and least favorite part of being a diplomat?

What I like most about being a diplomat is that you have such infinite possibilities: where you work and with whom on what issues can change with every new posting. The change keeps you constantly learning. My least favorite part is the moment when you have to move. Saying good-byes is always hard.

I know many of our readers are students, young scholars and young professionals. Would you like to share with us what, in your opinion, are some of the most important skills for an aspiring international lawyer to develop? Do you have any advice for them?

One of the most important skills is knowing what really matters, developing a kind of orientation compass that stops you from getting lost in too much information or sidetracked onto secondary issues. My advice would be: go to events such as panel talks and conferences, follow the debates and seek out the people that inspire you. Read the work of the people whose judgement you find convincing. Try out different types of work, so you can find your strengths and refine your thinking. Wherever possible, aim to reduce complexity, not add to it. Clarity is key.

Finally, would you like to share with us a highlight of your career? I would be interested in hearing from a project that was particularly close to your heart.

Pleading before the International Court of Justice was undoubtedly a highlight. The atmosphere is extraordinary, as is the honor to speak for your country. Arguing before the German Federal Constitutional Court is in a way even more exciting, because you have to respond to the Judges’ questions on the spot. Beyond the highlights, international law requires stamina. You have to have what Germans call a “long breath” for developments in international law, i. e. patience.

My own journey into international law began with a desire to work to protect human rights, including equality. I vividly remember the Rome Conference in 1998, when the International Criminal Court was established. That moment made a lasting impression on me, it made me even more determined to become a diplomat. And I have not regretted it since. We just negotiated at a Special Session of the Assembly of States Parties of the ICC on whether the jurisdiction of the ICC over the crime of aggression can be further adjusted. Progress takes time. Every time that I have had the chance to contribute even in a small way to an international legal policy that serves better protection for human rights or improves accountability for serious human rights violations, that is when my work has felt most meaningful.

Dear Dr. Rückert, thank you very much for taking the time for this interview and for sharing your views. I am confident that these insights and your advice for young readers will be greatly appreciated. It has been a pleasure to have you at the Völkerrechtsblog!

The pleasure was all mine! Thank you for the interview, Aurelio.