Bound to the Mast: Why Germany Binds Itself to International Law

[I. Introduction]

…

Why does Germany bind itself to international law?

Why would a State that possesses sovereignty voluntarily accept constraints on the exercise of that sovereignty? Why would a State accept the jurisdiction of international courts? Why would it accept treaty obligations that may constrain the freedom of a future government? And why would it sometimes go further and build those international commitments into its own constitutional order?

I would like to approach this question through an image from classical literature, and then through three themes that continue to shape German foreign policy: security, freedom and prosperity.

II. Bound to the Mast: The Question

Let me begin with the maritime image.

In Homer's Odyssey, Ulysses knows that he is about to encounter the Sirens. Their song is irresistible.

So he orders his crew to plug their ears with wax. But he himself wants to hear the song.

And so he gives his crew a very unusual order: tie me to the mast.

And then he tells them that, when he later begs them to release him, they must not listen to him.

They must tie him even more tightly.

Ulysses knows that his future self will be tempted. And so, while his judgement is still clear, he binds himself.

There are two details in this story that I find particularly useful when thinking about international law.

First, Ulysses still hears the song.

Self-binding does not mean becoming deaf to interests, to political pressures, or to power. It does not mean pretending that the world is without conflict. It means creating a boundary that prevents a moment of temptation from becoming a catastrophe.

Second, the crew who refuse to untie him are, in our modern analogy, the institutions: the treaties, the courts, the procedures and the other States that hold us to commitments even when the government of the day might prefer to escape them.

Ultimately, Ulysses' strategy is an exercise in precommitment. It is a story about foresight.

He acknowledges his own psychological weakness and builds a physical boundary beforehand.

And that brings us to the question I would like to address today:

Why would a State voluntarily accept legal constraints on its own freedom of action?

The thesis I would like to put forward is the following:

Self-binding is a strategy, not a sacrifice.

Binding oneself to rules recognised by the community of nations is not necessarily a limitation of sovereignty. It can be a safeguard for sovereignty.

And I would like to illustrate this argument first by looking at Germany's answer since 1949, and then by looking at three areas in which this logic of self-binding is particularly visible:

Security.

Freedom.

Prosperity.

III. Germany's Answer

The German answer to the question of international law was profoundly shaped by history.

The Federal Republic was founded in 1949 after a regime that had placed itself above law, above constitutional restraint and ultimately above the most basic principles of humanity.

The result was catastrophe: war, destruction, occupation, the Holocaust, and an indelible stain on German history.

The lesson drawn by the new Federal Republic was not that Germany should simply have less sovereignty.

The lesson was that sovereignty should be exercised within a legal and institutional framework.

This is reflected right at the beginning of the Basic Law, the Grundgesetz.

The Preamble commits Germany to “promote world peace as an equal partner in a united Europe”.

That formulation is important.

Germany's constitutional identity was not constructed around isolation. It was constructed around

integration: integration into Europe, integration into international cooperation, and integration into a legal order designed to preserve peace.

The constitutional provisions are striking.

Article 25 of the Basic Law provides that the general rules of international law form part of federal law and take precedence over ordinary statutes. This is one of the clearest constitutional expressions of Germany's commitment to international law.

Article 24 permits Germany to transfer sovereign powers to international organisations. It also permits participation in systems of mutual collective security and provides for accession to agreements providing for compulsory international arbitration for the peaceful settlement of disputes.

Article 23, the so-called Europa-Artikel, places European integration at the heart of the constitutional framework.

And Article 26 declares that acts tending to and undertaken with the intention of disturbing the peaceful relations between nations, especially preparing for a war of aggression, are unconstitutional and are to be criminalised.

Taken together, these provisions are not an incidental collection of constitutional clauses.

They express a particular conception of Germany's place in the world.

The Federal Constitutional Court has described this as the Basic Law's “friendliness towards international law” — Völkerrechtsfreundlichkeit.

In its 2004 Görgülü judgment, the Court explained that the Basic Law seeks to integrate Germany into an international legal order dedicated to peace and freedom, and that the constitutional framework facilitates international cooperation and seeks, wherever possible, to avoid conflicts between German law and Germany's international obligations.

At the same time, it is important to understand what this principle does not mean.

The German constitutional order does not simply surrender constitutional sovereignty to every international institution.

The Federal Constitutional Court has expressly emphasised that Germany remains a democratic constitutional State and that international commitments operate within the framework established by the Basic Law.

So the German approach is not: international law replaces constitutional democracy.

It is rather: constitutional democracy deliberately creates space for international law and international cooperation.

That distinction matters.

Germany has repeatedly made this choice.

In the 1950s, it joined the Council of Europe and accepted the European Convention on Human Rights.

It became part of the European Communities.

It joined NATO.

It joined the United Nations in 1973.

And in 2008 Germany accepted the compulsory jurisdiction of the International Court of Justice under Article 36, paragraph 2, of the ICJ Statute. The declaration stated that Germany recognised the Court's jurisdiction as compulsory, ipso facto and without special agreement, in relation to other States accepting the same obligation, subject to the terms of the declaration.

That is a particularly revealing example of self-binding.

We see the compulsory nature of the ICJ's jurisdiction as international law working as intended.

A State that accepts the jurisdiction of a court only when the acceptance seems comfortable has not accepted that jurisdiction at all.

The point of a commitment is precisely that it continues to bind when circumstances become difficult.

There is, of course, a political-science literature that describes this phenomenon as “strategic restraint”: States that bind themselves in institutions make their power more predictable and gain partners and legitimacy in return.

That is an important insight.

But I would add something from the German perspective.

For Germany, self-binding is not merely about making German power predictable to others.

It is also about making Germany's own future behaviour predictable to Germany itself.

And perhaps nowhere is this clearer than in 1990.

The reunification of Germany was not simply an event in which a sovereign State became larger.

German unity came together with legal commitments.

The Two-Plus-Four Treaty confirmed Germany's final borders, its commitments to peace, and important limitations concerning its military posture and weapons.

The treaty stated that only peace shall emanate from German soil.

The parties also dealt with the status and size of German armed forces and with Germany's commitments concerning nuclear, biological and chemical weapons.

The significance of this is easy to miss when we look back from the present.

German unity was not achieved by Germany deciding that, because it was becoming sovereign and united, it should be free from external constraints.

Quite the opposite.

Unity came together with international legal commitments.

Self-binding was the precondition of reunification, not its price.

That is an important distinction for understanding the German experience.

The lesson is that legal constraint can sometimes create political possibility.

VI. What Does It Mean for Germany Today?

Let me now turn from history and constitutional architecture to the present.

What does self-binding mean for Germany today?

I would like to organise this part around three central political leitmotifs and core objectives of German domestic and foreign policy: security, freedom and prosperity.

1. Security

The first question is what self-binding means for protection from external threats and for internal stability.

a) The UN Charter

At the most fundamental level, the rulebook is the United Nations Charter.

No State is above the law.

That is the cornerstone of sovereign equality and of the international rule of law.

The Charter begins from sovereign equality.

It requires the peaceful settlement of disputes.

It prohibits the threat or use of force against the territorial integrity or political independence of States, subject to the framework of the Charter, including the right of self-defence under Article 51.

This is not an abstract legal exercise.

It is a security architecture.

Why should adherence to these rules be in a State's own security interest?

Because predictability matters.

A State that knows that its neighbour is bound by rules has a different security relationship with that

neighbour than a State that believes its neighbour may redraw borders whenever it has sufficient military power to do so.

When States redraw borders by force, they do more than change one border.

They damage the rulebook on which they themselves may later depend.

The international order is not a one-way protection mechanism.

Every State may one day need the principles that it expects others to respect today.

This is why sovereign equality and the prohibition of force are not simply constraints on power.

They are also protections against the arbitrary exercise of power.

A State bound by rules is, at least in principle, more predictable to its neighbours.

Predictability reduces uncertainty.

And reducing uncertainty can reduce the security dilemma, rather than feeding it.

b) Germany is bound by alliances

This brings me to the second aspect of security: alliances.

For Germany, security in Europe has not been achieved simply by accumulating military force.

It has been achieved through alliances, institutions and shared rules.

NATO itself is a treaty.

Germany does not participate in NATO despite being bound by international law.

Germany participates in NATO through international law.

This is another important way of understanding self-binding.

A treaty can constrain the freedom of unilateral action while simultaneously increasing the security

available to all its parties.

The commitment becomes reciprocal.

I undertake obligations toward you because you undertake obligations toward me.

And the resulting predictability can be more valuable than the freedom to act alone.

c) Our borders defined by treaties

There is a third lesson that comes directly from Germany's own history.

Germany's borders in Europe were not ultimately determined by the range of artillery.

They were confirmed by treaties.

The Eastern Treaties of the 1970s, the Helsinki Final Act of 1975, and ultimately the settlement accompanying German reunification in 1990 all belong to this history.

The Helsinki Final Act included the principle of the inviolability of frontiers.

The Two-Plus-Four settlement provided the international legal framework for German unity and confirmed the final nature of Germany's external borders.

Germany's experience therefore offers a very concrete example of the proposition that borders can be defined “by the stroke of a pen” rather than “the reach of artillery”.

That is not simply a historical observation.

It is a statement about what international law can achieve.

The peaceful settlement of borders is one of the greatest achievements of a rules-based

international order because it changes the basic incentive structure between States.

d) Ukraine

And this brings me to Ukraine.

Europe's freedom and security are directly linked to the outcome of the war in Ukraine.

Russia's full-scale aggression against Ukraine has challenged fundamental principles of the European security order, including the prohibition on the use of force and the principle that borders cannot simply be changed through military aggression.

It has now been more than a decade since the annexation of Crimea, and more than four years since Russia's full-scale invasion.

Germany will continue to support Ukraine in its defence against Russian aggression.

For Germany, this is not only about one country's territorial integrity.

It is also about the rules governing the European security order.

If the principle that borders cannot be changed by force is weakened, the uncertainty does not stop at the border of Ukraine.

The question is therefore not whether international law is relevant to European security.

The question is whether European security can remain stable without the basic rules of international law.

And Germany's answer is clear: security requires both capabilities and rules.

Military capability matters.

Alliances matter.

Deterrence matters.

But without rules, those instruments operate in a world of permanent uncertainty.

2. Freedom

The second theme is freedom.

For Germany, freedom is not simply the absence of external constraint.

It means respect for basic human rights, the rule of law, and living in a society based on democratic values.

And in this sense, I would put the proposition quite starkly:

Impunity is the enemy of freedom.

If individuals who commit the gravest international crimes can rely on their political position or military power to shield them from accountability, then law becomes conditional on power.

And once law becomes conditional on power, freedom becomes conditional as well.

This brings me to Nuremberg.

This week, it will be exactly 80 years since the International Military Tribunal at Nuremberg delivered its judgment.

Nuremberg was itself an extraordinary act of self-binding by the victors.

Robert H. Jackson, Chief Counsel for the United States at the International Military Tribunal, said in his opening statement in Nuremberg on 21 November 1945:

“That four great nations, flushed with victory and stung with injury stay the hand of vengeance and voluntarily submit their captive enemies to the judgment of the law is one of the most significant tributes that Power has ever paid to Reason.”

That sentence captures something fundamental.

The victorious powers could have exercised power as victors.

Instead, they chose to place the exercise of that power within a judicial process.

Nuremberg therefore was not simply a trial of German leaders.

It was men, not by abstract entities, also a statement about the relationship between power and law.

And the Tribunal formulated another principle that became foundational for international criminal law:

“Crimes against international law are committed by men, not by abstract entities, and only by punishing individuals who commit such crimes can the provisions of international law be enforced.”

For Germany, this is a lesson of its own history.

The Nuremberg principles were applied to Germany before Germany embraced them as part of its own commitment to international criminal justice.

Today, the International Nuremberg Principles Academy in Nuremberg is dedicated to the promotion of international criminal justice and human rights.

And this historical experience helps explain Germany's commitment to the International Criminal

Court.

Germany is a founding State Party to the Rome Statute. It signed the Statute in 1998 and ratified it in 2000, becoming its 25th State Party. Germany subsequently enacted the Code of Crimes against

International Law in 2002, providing a domestic legal basis for the prosecution of serious international crimes.

This is another example of self-binding.

Germany does not say: international criminal law should apply to other States.

Germany accepts that the same principles should apply to Germany.

And this is precisely what gives the idea of international criminal justice its force.

The rule of law cannot credibly mean that accountability is reserved for one's adversaries.

It must also apply when the legal process is politically uncomfortable.

It must apply when the defendant is powerful. It must apply when the facts are difficult.

And it must apply when the international community itself is divided.

That is why institutions such as the ICC matter.

Germany has repeatedly expressed its support for the Court as an institution central to the fight

against impunity for the most serious crimes affecting the international community, particularly where national jurisdictions are unable or unwilling genuinely to act.

Germany's position is rooted not only in contemporary foreign policy but also in historical experience.

Germany knows what can happen when State power overrides law and humanity.

And that is why, for Germany, support for international criminal justice is not only a question of foreign policy.

It is also part of historical responsibility.

V. Prosperity: The Invisible Infrastructure

Let me now turn to the third theme: prosperity.

I would describe international law as the invisible infrastructure of global prosperity.

We tend to notice infrastructure when it fails.

We notice a bridge when it collapses. We notice an air-traffic system when flights cannot operate.

International law is similar. When it works, it can be almost invisible.

Ships arrive. Aircraft land. Goods cross borders. Investments take place.

And much of this depends on rules that most people never see.

Germany is a particularly good example.

Germany is a trading nation. Exports of goods and services amounted to approximately 42.1 percent of German GDP in 2024.

German prosperity therefore depends to a considerable degree on the ability to trade, invest and compete internationally.

And this requires a legal framework.

Germany's interest is not in a system in which the strongest State simply dictates the terms of trade.

It is in a system in which competition takes place within predictable rules.

Here in Singapore, if we look at the sea lanes and air traffic routes as the vital arteries of global trade, this becomes obvious in very practical terms.

Take civil aviation.

Without the Chicago Convention — the principal international treaty governing international civil aviation and the treaty that established the International Civil Aviation Organization, ICAO — the business models of Lufthansa or Singapore Airlines would be fundamentally more difficult to sustain.

Without the United Nations Convention on the Law of the Sea, UNCLOS, shipping companies such as

Hapag-Lloyd or Pacific International Lines would face a much greater degree of legal uncertainty.

And I am very conscious that UNCLOS is a subject that justifies a separate lecture — for which there are many more qualified people in this room.

Let me therefore limit myself to one point that is particularly relevant to this region.

Germany acknowledges the right, enshrined in the Convention, of transit passage through straits used for international navigation.

That principle must be upheld without compromise.

As a user State of the Straits of Malacca and Singapore, Germany benefits directly from the stability and predictability of this legal framework.

And Germany is grateful for the cooperation of the littoral States — Malaysia, Indonesia and Singapore — as I underlined recently at the Forum of the Cooperative Mechanism here in Singapore.

This is a perfect illustration of what I mean by the invisible infrastructure of prosperity.

The same logic applies to international trade.

For many decades, the World Trade Organization has played an important role in creating a predictable, rules-based system for global trade.

Germany has a profound economic interest in such a system.

And although we are all aware that the WTO today is not functioning as effectively as it was designed to — particularly in relation to dispute settlement and the difficulty of negotiating new multilateral rules — its basic trading system remains highly significant.

According to the WTO's latest figures, around 72 percent of world merchandise trade continues to take place under most-favoured-nation terms.

That means that the WTO's non-discrimination framework still covers a very large share of world trade. The lesson is that even an institution experiencing serious difficulties can remain part of the

legal infrastructure on which global commerce depends.

And that brings me to the most significant example of self-binding as a strategy, and perhaps the most consequential example for European prosperity:

European integration.

The European project is, in many respects, an extraordinary experiment in mutual self-binding.

After 1945, European States faced a question that was both political and economic:

How could former enemies create a system in which war would not merely be undesirable, but increasingly irrational and structurally difficult?

The answer was not to eliminate national sovereignty overnight.

The answer was to pool and constrain the exercise of sovereignty in selected areas.

The European Coal and Steel Community placed the production of coal and steel — the materials of industrial power and, at the time, of military power — within a common institutional framework.

The Treaty of Rome then expanded the project.

Over the following decades, the European Communities developed into the European Union.

The Single Market created a common economic space based on common rules.

And Germany, together with its European partners, accepted that many decisions affecting its economic life would be taken through European institutions and according to common European law.

From a narrow conception of sovereignty, this can look like a loss.

From the perspective of strategic restraint, it looks very different.

Germany gained something in return: access to a vast common market, predictable rules, freedom of movement, common institutions, and — above all — a European political and economic order in which the interests of neighbouring States became increasingly interdependent.

The transformation of Western Europe from the war-torn wastelands of 1945 into one of the world's

most prosperous economic regions was driven by many factors: reconstruction, the Marshall Plan, technological development, domestic economic policy, global trade, and the extraordinary efforts of European societies themselves.

But European integration provided something equally important:

a legal and institutional framework within which that prosperity could develop.

It transformed relations between former enemies.

The Franco-German relationship is perhaps the most obvious example.

The question was not simply how to prevent another war.

It was how to make the political and economic interests of the two countries so deeply intertwined that cooperation became the normal condition of their relationship.

That is the deeper meaning of European integration.

The European Union is therefore not simply a trade arrangement.

It is a particularly advanced form of self-binding.

Member States voluntarily accept common rules, common institutions and, in many fields, common decision-making because they judge that the benefits of acting together outweigh the benefits of acting entirely alone.

For Germany, this has been one of the most consequential strategic decisions of the post-war period.

And it also illustrates why we should be careful with the language of sovereignty.

Sovereignty is often presented as a choice between freedom and constraint.

But that is too simple.

Sometimes the choice is between formal freedom without influence and shared rules with greater collective influence.

Sometimes accepting a common rule gives a State more ability to shape the environment in which it operates than insisting on complete unilateral freedom would provide.

This is particularly visible for a country like Germany, whose economic prosperity depends heavily on

European and global markets.

Self-binding can therefore be a source of power.

It can make power more predictable, but it can also make power more effective.

That, I think, is one of the central lessons of the European experience.

VI. Conclusion: Back to the Mast

Let me come back to Ulysses.

What is the mast today?

For me, it is respect for the rules recognised by the community of nations.

It is the treaties. It is the courts. It is the institution.

It is the constitutional provision that tells a government: you may have political power today, but there are commitments that extend beyond the government of the day.

A wise leadership recognises that voluntarily binding oneself to a rules-based order is not a limitation

of sovereignty but a safeguard for it.

It creates predictability and trust. It makes cooperation possible.

It can reduce the security dilemma. It protects individual freedom.

It creates conditions for economic exchange.

And it provides a framework within which power itself can be exercised.

This does not mean that international law is perfect.

It does not mean that international institutions are perfect.

It does not mean that every treaty produces the outcome that every State wants.

And it certainly does not mean that Germany has always perfectly lived up to every international commitment it has undertaken.

The point is different.

The point is that Germany's post-war experience has led it to conclude that a world in which States

are free to disregard international law whenever it becomes inconvenient is ultimately less secure, less free and less prosperous.

The alternative is not a world without sovereignty.

It is a world in which sovereignty is exercised through rules.

And perhaps that is the most important lesson of the German experience.

Germany once experienced what happens when State power places itself above law.

After 1945, and constitutionally since 1949, Germany chose a different path.

It bound itself.

It bound itself to European integration, to collective security, to international human rights law, to international criminal justice. It bound itself to international courts.

It bound itself to a multilateral trading system.

And it did so because the lesson of history was not that Germany needed less sovereignty.

It was that sovereignty without rules can become dangerous — to others, and ultimately to the sovereign itself.

The international order today is under enormous pressure.

Some of the rules that seemed secure for decades are being challenged.

Institutions are under strain.

International courts face political pressure.

The multilateral trading system is being tested.

The prohibition on the use of force is being challenged.

And there is a growing temptation, in many parts of the world, to ask whether rules still serve

national interests when circumstances change.

My answer, from the German perspective, is that this is precisely when the logic of self-binding

becomes most important.

The value of a rule is not measured only by how useful it is when everyone agrees.

Its value is tested when circumstances become difficult.

The value of a commitment is not that it binds us when we want to be bound.

It is that it provides a framework when interests diverge.

And the value of international law is not that it eliminates power.

It is that it seeks to put power within a framework that makes peaceful coexistence possible.

So let me end where I began.

Ulysses hears the song.

He does not pretend that temptation does not exist.

He does not surrender his freedom to hear it.

But he recognises that, in a moment of weakness, he may make a decision that his rational self would

regret.

So he binds himself to the mast.

For Germany, the mast today is the international legal order.

Germany and Singapore have very different histories.

But perhaps there is a common conclusion.

Both countries have a profound interest in an international environment in which rules matter, in which agreements are respected, in which international navigation remains open, in which trade can flow, in which sovereignty is protected by law rather than by force, and in which disputes can be addressed through institutions rather than through violence.

Germany and Singapore are, in different ways and from different historical experiences, partners in keeping that rulebook working.

And perhaps that is the final point I would leave with you:

Self-binding is not the opposite of sovereignty.

Sometimes, it is how sovereignty becomes sustainable.

And, ultimately, it is one of the ways in which we can keep the ship of State clear of political risk and of what Abraham Lincoln called “the mighty scourge of war”.

Thank you very much for your attention.