The conventional narrative surrounding the League of Nations' failure places primary blame on American isolationism and the United States Senate's refusal to ratify membership. This explanation, while convenient for European powers seeking to deflect responsibility, fundamentally misunderstands both the League's structure and the realities of early 20th-century global power. The League of Nations did not fail because America stayed home—it failed because Britain and France, who possessed unprecedented global reach and resources, chose colonial self-interest over collective security and lacked the moral courage to confront aggression when it mattered most.
By 1920, the British and French Empires together controlled an astounding 32% of the world's land area and governed close to 28% of the global population. The British Empire alone, at its height after the Great War, encompassed 24% of world territory and ruled over 23% of humanity, while France controlled approximately 8% of global landmass and 5% of the world's people. These were not minor players hoping for American leadership—they were the dominant global powers of their age, possessing the military, economic, and administrative capabilities to enforce international law across continents.
Rather than using this unprecedented power to build genuine international cooperation, Britain and France immediately prioritized imperial expansion. The 1920 San Remo Conference revealed their true priorities: carving up the Ottoman Empire's territories not as steps toward independence, but as new imperial possessions disguised as League mandates. France secured control over Syria and Lebanon, while Britain claimed Palestine and Iraq. The Anglo-French oil agreement concluded during the same conference—guaranteeing France 25% of Iraqi oil in exchange for supporting British control over Mosul—exposed the naked economic imperialism driving their decisions.
The mandate system itself became a masterpiece of imperial doublespeak. Theoretically designed to prepare territories for self-governance under League supervision, the mandates functioned as traditional colonies in all but name. Here is how it worked: League of Nations mandates were authorizations granted to member nations by the League to govern former colonies of Germany or the Ottoman Empire. These territories were considered, almost, but just not quite not yet ready to govern themselves after the Great War.
The mandate system was a compromise — a largely rhetorical one —between the Allies who wanted to take the colonies of their defeated enemies, and their war propaganda declaration that the annexation of territory was not a war aim. The mandates were divided into three classes based on their location, political, and economic development, and then assigned to Allied victors.
The three classes were:
Class A mandates Former Turkish provinces like Iraq, Syria, Lebanon, and Palestine. These territories were considered advanced enough for provisional independence but were still subject to Allied administrative control until fully independent. (Out this came the Israeli-Arab conflict.)
Class B mandates Former German-ruled African colonies like Tanganyika, parts of Togoland and Cameroons, and Ruanda-Urundi. The Allied powers were directly responsible for the administration of these mandates but were subject to certain controls intended to protect the rights of the mandates’ native peoples.
Class C mandates Various former German-held territories that the assigned Mandatories subsequently administered as integral parts of their territory, such as South West Africa (now Namibia, assigned to South Africa, part of the British Empire), New Guinea (assigned to Australia, part of the British Empire), Western Samoa (now Samoa, assigned to New Zealand, part of the British Empire), the islands north of the Equator in the western Pacific (Japan), and Nauru (Australia, with Britain and New Zealand).
The League’s Permanent Mandates Commission theoretically supervised the exercise of the mandates. In 1946, the UN trusteeship system replaced the mandate system. Focusing on Class A makes this clearer. The Class A mandates of Iraq, Syria, Lebanon, and Palestine were supposedly "advanced enough for provisional independence," yet remained under direct Allied administrative control. The League's Permanent Mandates Commission provided only theoretical oversight, lacking real power to enforce mandate terms or hold mandatory powers accountable. So, Britain and France had created a system expanding their empires under the banner of international cooperation. How will become clear in a moment as the mask slipped early.
When they carved the map up during the San Remo Conference in 1920, Britain and France sliced Ottoman lands into the mandates, not as pathways to self-rule but as new dependencies branded with League approval. France took Syria and Lebanon. Britain took Palestine and Iraq. An Anglo-French oil deal sweetened the arrangement—France would receive a quarter share of Iraqi oil in exchange for accepting British control over Mosul. Call it diplomacy if you like. It was resource extraction with polite paperwork. The League's governing structure reinforced British-French dominance. When the United States declined membership, the League Council—originally designed for five great powers—became dominated by Britain and France, who together with Italy and Japan formed the permanent membership. In essence, the colonizers were supervising themselves, wielding disproportionate influence over an organization theoretically dedicated to collective security and self-determination.
This double game destroyed trust. How could small nations or colonized peoples believe in an international order that preached nonaggression while its stewards expanded their own sway? Many saw the truth at once: the League’s promises of tutelage were a holding pattern for European control, not a road to sovereignty. Moral authority drained out of the project from the start. That was a choice of the French and the British. The mandate system's hypocrisy was evident to colonized peoples who began to challenge, often violently, the claims of their would-be European masters. The only way for the Europeans to make this an “America missing in action” problem would be the expectation that the US would have restrained Britain and France, —by force one assumes —likely not what British and French apologists are advocating for.
The consequences of this moral bankruptcy became clear when the League faced its first serious challenges. Britain and France had the military and economic resources to stop aggression—their combined empires could field massive armies; they still controlled crucial trade routes. If they collaborated, they could have enforced the League of Nations charter, and put Japan, Italy and even Germany in their place.
American absence, while perhaps unfortunate, cannot excuse this failure of leadership. Britain and France made the conscious choice to join the League, accepting the responsibilities of membership while simultaneously undermining its principles through their colonial policies. You cannot claim the benefits of League membership—legitimacy for their mandates and justification for their expanded empires—while rejecting responsibility for making the organization effective. The claim that the League was doomed without the United States mistakes structure for character. Institutions can amplify power; they cannot supply courage. The order was theirs to defend. What they lacked was the political and moral will to treat aggression against others like China and Ethiopia as aggression against themselves or the League system they dominated. They preferred quiet over risk and resistance, imperial gain over collective duty. When the reckoning came, they stood atop an institution they had weakened to point of being irrelevant. The tragedy of the League is not primarily an American story. It cannot be. It is one of European stewardship abused. London and Paris turned an chance for global collective security into a cover for imperial expansion, then found themselves unwilling—or unable—to defend even that compromised system when confronted by rival imperialisms. The verdict of guilt belongs where the power was: in British and French cabinets that possessed the means to make the League work and chose otherwise.
International orders do not collapse simply because outsiders refuse to join. They collapse when insiders trade principle for convenience or greed, and hope that signatures can substitute for resolve. The work of peace is not some mysterious, unknowable thing. It requires hard work and disciplined choices. Integrity and firmness. The League failed where its stewards faltered. Any successor worth the name must do better—choose duty over alibis, enforcement over euphemism, and courage over comfort. The United Nations has work to do.