The power and constraints on international law in a political world

International courts have become central actors in global governance, playing a powerful role in shaping political life far beyond the courtroom. Yet despite their growing reach and the uniformity of the international statutes they follow, they do not always act in the same way. Sometimes they push back forcefully against states. At other moments, they exercise surprising restraint.

Dr Theresa Squatrito, Associate Professor in the Department of International Relations at LSE, has been examining this variation. Her new book, Judging Under Constraint: the politics of deference by international courts, asks a question that sits at the heart of today’s international legal order: why do some international courts challenge governments, while others choose not to? Her research, the focus of a recent LSE Research Showcase talk, sheds fresh light on how courts navigate political pressures, what shapes their choices, and why it matters for justice and the rule‑based international order.

A world increasingly governed by law

“International courts exist today on a scale never seen before,” explains Dr Squatrito. “Much of international relations now operates through legal and judicial processes, and one development that is at the core of the legalisation and judicialisation of world politics is the proliferation of international courts. These institutions are a bedrock of the international rule-based order.”

Since the end of the Second World War, dozens of new judicial bodies have been created. Today, 23 permanent international courts are in operation, ruling on legal disputes between sovereign states, prosecuting individuals for grave crimes and providing advisory opinions to international organisations. As a result, treaties, rules and institutions govern everything from trade and migration to the conduct of war and protection of human rights.

These institutions underpin the international rule‑based system, offering a forum where disputes can be settled, rights vindicated, and states held accountable for their legal commitments. “International courts are increasingly expected to clarify international law, settle disputes and hold states accountable,” says Dr Squatrito. “And yet courts serve these roles in different ways.” Understanding why is crucial for grasping the kind of justice – and the kind of politics – that emerges from global institutions.

Courts must appear a neutral arbiter. But they also rely on states for funding, for appointing judges and – crucially – to implement their decisions.

What international courts do

Although the work of international courts often only makes headlines when the gravest events are being ruled on, their impact is far more wide-reaching. They play key functions in regulating international and regional affairs and delivering rulings that can impact domestic, social, political and economic life.

International courts have three key roles to play in upholding international order, explains Dr Squatrito.

First, they help ensure state compliance with international obligations. She cites a case ruled on by the Caribbean Court of Justice (CCJ) over whether Barbados was upholding its commitments to ensure that citizens of Caribbean Community states were able to enter without hassle – a right upheld by law in a way similar to the EU’s freedom of movement. “This case was brought to the Court by a Jamaican woman who had been detained, harassed and invasively searched before being expelled from Barbados. In this instance, the Court ruled that Barbados had failed to comply with its obligations,” Dr Squatrito says.

Second, international courts settle disputes. “The East African Court of Justice (EACJ), for instance, has recently been asked to adjudicate a dispute between the Democratic Republic of Congo and Rwanda. The DRC alleges that Rwandan military forces have been conducting acts of aggression in the North Kivu region, violating the DRC’s sovereignty, territorial integrity, political stability and independence. While the outcome hasn’t been delivered yet, how the Court rules will have important implications, not just for this dispute but arguably for future ones.”

Third, these courts interpret the law, setting standards that can reshape domestic legislation. Dr Squatrito gives the example of the African Court on Human and Peoples’ Rights (AfCHPR), which was asked to assess whether Mali’s family law – which created different rules for boys and girls – violated African human rights standards. “The Court ruled decisively that it did, and as a result, Mali was required to amend its domestic legislation,” she explains.

This raises the question: with such significant authority, why do some courts “push back” against states, while others appear to accept how states exercise their authority? The answer, Dr Squatrito argues, lies in the concept of “judicial deference”.

International institutions are vulnerable to power politics, but they can exercise agency to accommodate their constraints and remain resilient.

What is judicial deference and how does it impact international law?

A court shows deference, Dr Squatrito explains, when it validates a government’s actions or legal position – or declines to intervene, even where international law might allow it.

“I measure deference along three dimensions of a judicial decision,” she says. “First, case outcomes, such as when a court finds no violation. Second, legal reasoning, when courts interpret the law in a way that minimally restricts state sovereignty. Finally, remedies – when courts avoid imposing strong corrective measures on states.”

“Different courts exhibit different levels of deference,” she continues. “The AfCHPR, for example, did not hesitate in ruling that Mali’s interpretation of human rights law was inconsistent with its obligations. By contrast, the EACJ dismissed a case against Uganda in which it was alleged to have violently supressed protesters, despite the fact that these abuses had been widely documented.”

The central question, then, is: what drives these differences?

Strategic space: how courts navigate politics

At the heart of Dr Squatrito’s argument is the concept of strategic space – the political and institutional room within which a court can manoeuvre.

International courts face two competing pressures: legal legitimacy – the need to appear neutral and impartial; and political survival and compliance – the need to avoid provoking states to the point of resistance.

"Courts must appear a neutral arbiter,” she explains. “But they also rely on states for funding, for appointing judges and – crucially – to implement their decisions. This creates pressure to rule in ways that avoids backlash or defiance.”

Two structural factors shape a court’s strategic space. First, a court’s institutional safeguards for independence – for example, rules around judicial appointments, budget control and tenure all determine a court’s legitimacy and how feasible it is for states to curb its authority.

Second, the degree of political fragmentation between member states, with high fragmentation appearing to strengthen a court's position. “If states have very different views, they will rarely be able to coordinate enough to punish a court," says Dr Squatrito. High fragmentation therefore expands a court’s strategic space.

The traditional view was that the post-World War rule-based order was beneficial particularly because it depoliticised international politics … [but] this view overlooked how law and courts are themselves constrained by politics.

A comparison of three regional courts

Judging Under Constraint tests this argument by examining three international courts: the East African Court of Justice (EACJ), the Caribbean Court of Justice (CCJ); and the African Court on Human and Peoples’ Rights (AfCHPR). Each is relatively young – all were established in the early 21st century – and all serve regions shaped by colonial legacies, legal pluralism, and uneven access to justice.

The EACJ, Dr Squatrito finds, operates within the narrowest strategic space, shaped by low formal independence and moderate fragmentation. This explains the “substantial deference” demonstrated by the Court.

The CCJ, benefits from high independence and relative political unity among Caribbean Community states, giving it broader room to manoeuvre and producing moderate deference. “The CCJ has ruled in favour of states in one third of cases, while applying heightened scrutiny over states and purposeful interpretation of the law,” says Dr Squatrito. “It does not shy away from ordering states to remedy their wrongs.”

The AfCHPR enjoys the broadest strategic space, due to high independence and significant political fragmentation among African Union members. It therefore faces fewer political constraints and exhibits low deference, ruling in favour of states only 18 per cent of the time and issuing robust remedies, including ordering legal reforms, compensation and restitution.

While the space these courts operate in varies, all three have developed strategic practices to navigate political pressure. Courts, Dr Squatrito emphasises, are not straitjacketed by their place in the wider political landscape. “The real power of courts lies not in the sword or the purse but in the power of argument,” she says. “By crafting persuasive arguments, courts can essentially broaden their strategic space.”

Courts also increasingly engage in public legitimisation – what might look like PR campaigning – to build public trust and demonstrate their relevance. “These practices help facilitate non-deference, especially when that strategic space is rather narrow.”

What international courts tell us about international justice

The findings offer several important insights.

First, that the rule-based order is not apolitical: “Five or ten years ago, the traditional view was that the post-World War rule-based order was beneficial particularly because it depoliticised international politics,” says Dr Squatrito. “My book, however, demonstrates that this view overlooked how law and courts are themselves constrained by politics.”

Second, the research has implications for how we understand judicial performance, showing political constraints vary depending on institutional safeguards and political fragmentation. “High independence and fragmentation enable impactful judicial decisions.”

Third, institutional resilience matters. Courts must navigate increasingly competitive and politicised landscapes, and their practices can help them survive political backlash.

“Strategic space is adaptable,” continues Dr Squatrito. “International institutions are vulnerable to power politics, but they can exercise agency to accommodate their constraints and remain resilient.”

Finally, institutional design matters for state accountability. Variation in judicial deference affects human rights, dispute settlement and the enforcement of international norms. Courts with greater strategic space are more able – and more willing – to hold governments to account.

As global challenges multiply, international courts remain vital venues for accountability, dispute resolution and the protection of rights. But as Judging Under Constraint shows, their ability to perform these functions depends not only on legal doctrine but also on the political realities they face.

By examining how and why courts defer to states, Dr Squatrito’s research provides a clearer understanding of the conditions under which international law can truly constrain power – and where its limits lie.

This Research Showcase talk was written up by Jess Winterstein, Deputy Head of Media Relations at LSE.

LSE Research Showcase is a series of 20-minute talks from LSE researchers to enjoy on your coffee break. Catch up on YouTube.

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