The United States’ foreign policy has oscillated between engagement and isolationism throughout its history. In the 1920s and 1930s, the US adopted a largely isolationist stance, exemplified by its refusal to join the League of Nations and the implementation of protectionist economic measures. This inward focus is paralleled in recent times by actions such as Secretary of State Marco Rubio’s decision to skip the G20 meeting in South Africa, citing the host nation’s policies as “anti-American.”
Historical Context: US Isolationism in the Interwar Period
After World War I, the US Senate rejected the Treaty of Versailles in 1920, which included provisions for the League of Nations—a body US President Woodrow Wilson had championed. This decision was rooted in a desire to avoid entangling alliances and foreign conflicts. The era also saw the enactment of high tariffs, such as the Fordney-McCumber Tariff of 1922, designed to protect domestic industries but which inadvertently strained international economic relations.
Marco Rubio’s G20 Absence: A Modern Reflection of Isolationism
In February 2025, Secretary Rubio announced he would not attend the G20 foreign ministers meeting in Johannesburg. He criticised South Africa’s focus on themes like “global inclusion” and “equity,” stating, “My job is to advance America’s national interests, not waste taxpayer money or coddle anti-Americanism.”
This sentiment mirrors the isolationist rhetoric of the interwar period, where US leaders prioritised national interests over international collaboration. The refusal to engage in multilateral forums then, as now, reflects a scepticism towards global institutions perceived as misaligned with American priorities.
Parallels with the League of Nations Rejection
The US abstention from the League of Nations was a significant manifestation of its isolationist policy. Concerns over sovereignty and entanglement in foreign disputes led to this decision, which some historians argue weakened the League’s effectiveness and emboldened aggressive regimes in Europe.
Similarly, Rubio’s decision to forgo the G20 meeting may signal a retreat from multilateral engagement, potentially diminishing the US’s influence in global decision-making and creating a vacuum that other powers could fill.
Trump Administration’s Stance on Multilateral Institutions
During his first term, President Donald Trump exhibited a contentious relationship with international organisations, criticising the United Nations and withdrawing from agreements he deemed unfavourable. In his second term, this trend appears to continue, with significant cuts to federal agencies supporting interventionist US foreign policies and strained relations with European allies over issues like Ukraine.
The administration’s approach suggests a preference for unilateral action over multilateral cooperation, reminiscent of the isolationist policies of the early 20th century.
Contrasting International Perspectives
French Foreign Minister Jean-Noël Barrot, ahead of the same G20 meeting, emphasised the importance of a rules-based international order, stating, “The discussion we should be having… is not the clash between north and south, but between those who support the law and those who support power by force.”
This perspective underscores a commitment to multilateralism and collective security, contrasting sharply with the US’s current isolationist tendencies.
Historical Lessons and Contemporary Implications
The isolationism of the 1920s and 1930s is often cited as a factor that allowed fascist regimes in Europe to pursue expansionist policies unchecked, culminating in World War II. Greater American engagement during that period might have deterred such aggression. The establishment of the United Nations post-World War II aimed to prevent similar global conflicts through a rules-based order, with the US playing a pivotal role.
Today, Russia’s actions in Ukraine challenge this international order. A US retreat from multilateral institutions could embolden such aggressors, leading to increased global instability. While these institutions are imperfect and in need of reform, they serve as platforms for promoting democracy and the rule of law. Disengagement may offer short-term savings but risks long-term consequences, including the potential for broader conflicts that could eventually draw the U.S. into war.
Conclusion
The echoes of past isolationism in current US foreign policy decisions, such as Secretary Rubio’s G20 absence, highlight the delicate balance between national interests and global responsibilities. History suggests that retreating from international engagement can lead to unintended and far-reaching consequences. As new challenges emerge, the US must carefully consider the lessons of the past to navigate its role on the world stage effectively.