A Century After the Slavery Convention, Freedom Still Has an Enforcement Problem

A century after governments signed the Slavery Convention in Geneva on September 25, 1926, the document still poses a direct question: what does it take to end a practice that the law has already condemned? The treaty gave the world a durable definition of slavery, yet its promise depended on what governments did after signing.

Article 1 defined slavery through the exercise of powers associated with ownership over a person. Article 2 required parties to suppress the slave trade and bring about the abolition of slavery “progressively and as soon as possible.” Those words mattered: they named a wrong and assigned responsibility, while leaving the pace and methods of enforcement largely to states. The treaty text shows both the ambition and the limits of that bargain.

A definition that did not settle every form of coercion

The convention also warned that compulsory or forced labour could develop into conditions analogous to slavery. But Article 5 allowed forced labour for public purposes and included transitional language for territories where other compulsory labour survived. Article 9 let a party exempt certain territories from some provisions. These clauses reflect the political compromises of an era when colonial rule was still widespread. They are part of the legal record, not a reason to treat the convention as an instant end to exploitation.

Modern estimates measure a related but broader problem. The International Labour Organization, International Organization for Migration and Walk Free estimated that 50 million people lived in what their report calls “modern slavery” in 2021: about 28 million in forced labour and 22 million in forced marriage. Those are 2021 estimates published in 2022, not a head count for this anniversary. The ILO’s explanation of the figures says its statistical umbrella covers exploitation people cannot refuse or leave because of coercion, deception or abuse of power.

The distinction matters. The treaty’s ownership-based definition and the report’s measure of forced labour and forced marriage are not interchangeable legal categories. Counting every case in the report as an Article 1 violation would blur the legal test; ignoring those cases because they do not all fit that test would miss the lived reality the estimate is meant to reveal.

The Palais des Nations in Geneva, photographed in 2014. The image is illustrative; it does not depict the 1926 signing. Photo: Vassil / Wikimedia Commons, CC0.

Where the enforcement question now sits

The ILO’s 2022 findings show why the issue cannot be assigned only to distant or low-income countries. More than half of the forced labour counted in the report occurred in upper-middle-income or high-income countries. Most cases of forced labour were in the private sector. Those figures make labour inspection, recruitment practices and supply-chain accountability practical tests of a government’s commitment, alongside criminal prohibition.

The same report found that migrant workers were more than three times as likely to be in forced labour as non-migrant adult workers. It recommended fair recruitment, stronger legal protections and social support, as well as measures to end state-imposed forced labour. These are policy recommendations from the reporting agencies, not evidence that any particular government or company has failed the treaty.

Forced marriage adds another challenge. The report estimated 22 million people living in forced marriages on any given day in 2021 and cautioned that its method likely misses some cases. A legal framework focused only on sale or formal ownership cannot by itself explain every relationship maintained through pressure, threats or an inability to leave. The broader measure calls attention to those conditions while still requiring precise law and careful evidence in individual cases.

A centennial measured in outcomes

The convention did not create a single global enforcement agency. It asked states to prevent and suppress the trade, abolish slavery and assist one another. Its centennial is therefore a useful point to test implementation: whether authorities identify coercion, protect people who report it, investigate those who profit, and remove the incentives that let it recur.

The numbers cannot tell us how many people are affected in September 2026. They do tell us that, in the latest global estimate cited here, legal condemnation had not produced freedom for tens of millions. A century after the convention, the strongest reading of its promise is neither a claim that nothing changed nor a declaration of victory. It is a demand to measure abolition by the ability of people to leave exploitation in practice.