Key facts and dates

The Second World War profoundly reshaped diplomatic relations across the Americas, marking the United States' rise as a global superpower and altering inter-American dynamics. The following timeline captures pivotal events and agreements that influenced power structures and set the stage for Cold War tensions in the region.

Timeline of key events

• 1945 (February) – Yalta Conference reveals early Cold War tensions between the US and USSR.
• 1945 (March) – Argentina declares war on Axis powers, ending prolonged neutrality.
• 1945 (April-June) – United Nations established, with significant US involvement.
• 1945 (July-August) – Potsdam Conference further highlights US-Soviet divisions.
• 1946 – US publishes "Blue Book" criticising Argentina's wartime neutrality.
• 1947 – Inter-American Treaty of Reciprocal Assistance (Rio Treaty) signed for mutual defence.
• 1948 – Organisation of American States (OAS) founded to promote hemispheric cooperation.

The United States' emergence as a superpower

The Second World War marked a turning point for the United States, transforming it from a nation focused on isolationism to a leading global power. Before the war, the US had largely avoided entanglement in European conflicts, adhering to a policy of non-intervention. However, the attack on Pearl Harbor in 1941 and subsequent involvement in the war shifted this stance dramatically.

From isolationism to global engagement

• Pre-war isolationism - Rooted in the aftermath of WWI, the US prioritised domestic issues over international alliances, reflected in policies like the Neutrality Acts of the 1930s which limited involvement in foreign wars.
• Wartime shift - The war necessitated active participation, with the US providing military and economic support through initiatives like the Lend-Lease Act, positioning it as a key Allied power.
• Post-war leadership - Victory in 1945, coupled with economic strength and military might (including the development of nuclear weapons), established the US as a superpower, ready to shape global politics in opposition to the Soviet Union.

Key wartime and post-war diplomatic developments

During and after WWII, significant diplomatic meetings laid the groundwork for the post-war world order, with the United States playing a central role. These events not only highlighted the US's new global status but also revealed emerging tensions that would define the Cold War.

Crucial conferences and their outcomes

• Yalta Conference (February 1945) - Held between the US, USSR, and UK, this meeting aimed to plan the post-war reorganisation of Europe. It exposed early divisions over issues like the future of Germany and Eastern Europe, with the US advocating for democratic principles while the USSR pushed for territorial control, planting seeds of Cold War rivalry.
• Potsdam Conference (July-August 1945) - Following Germany's surrender, this conference addressed post-war boundaries and reparations. Disagreements between US President Truman and Stalin over Soviet influence in Eastern Europe further strained relations, solidifying the US commitment to containing communism.
• Foundation of US leadership - These conferences positioned the US as the leader of the Western bloc, committed to rebuilding Europe through initiatives like the Marshall Plan and countering Soviet expansion, setting the stage for decades of ideological conflict.

The United States' role in post-war international and hemispheric organisations

In the war's aftermath, the United States spearheaded efforts to create new international and regional frameworks to ensure stability and cooperation. These organisations reflected its desire to maintain influence both globally and within the Americas.

Establishment of key organisations

• United Nations (1945) - Founded in San Francisco, the UN aimed to promote global peace and cooperation, replacing the ineffective League of Nations. The US played a leading role in its creation, hosting the founding conference and securing a permanent seat on the Security Council, which reinforced its diplomatic dominance.
• Inter-American Treaty of Reciprocal Assistance (Rio Treaty, 1947) - Signed in Rio de Janeiro, this mutual defence pact committed signatories in the Americas to collective security, stating that an attack on one was an attack on all. It was a direct response to emerging Cold War threats and a means for the US to solidify its regional leadership.
• Organisation of American States (OAS, 1948) - Established in Bogotá, the OAS aimed to foster hemispheric cooperation on political, economic, and social issues. It built on earlier Pan-American initiatives, with the US pushing for anti-communist unity as a core principle, reflecting its post-war strategic priorities.

Argentina's diplomatic challenges and isolation

While most Latin American countries aligned with the Allies during WWII, Argentina's stance was markedly different, leading to significant diplomatic repercussions. Its delayed entry into the war and perceived sympathies with the Axis powers created tensions with the United States and other hemispheric partners.

Argentina's wartime neutrality and consequences

• Prolonged neutrality - Argentina maintained neutrality for much of the war, driven by economic ties with both Allied and Axis nations, as well as internal political divisions. This stance frustrated the US, which sought unified hemispheric support against the Axis.
• Declaration of war (March 1945) - Only in the final months of the conflict did Argentina declare war on Germany and Japan, a move seen as opportunistic rather than principled, failing to mend strained relations with the US and Allies.
• The "Blue Book" controversy (1946) - Published by the US State Department, this report accused Argentina of harbouring Axis sympathisers and aiding Nazi war criminals during its neutrality. It intensified Argentina's diplomatic isolation, portraying it as unreliable within inter-American circles.
• Challenges of reintegration - Post-war, Argentina struggled to regain trust, facing strong US opposition to its participation in the UN founding conference (though it ultimately became a founding member in 1945) and criticism at hemispheric conferences. Under Juan Perón's leadership, it slowly sought to rebuild ties by aligning with anti-communist rhetoric during the Cold War.

The reconfiguration of inter-American relations and Cold War alignments

WWII fundamentally altered diplomatic relationships within the Americas, as the United States sought to maintain influence through policies and agreements. The war's end also introduced Cold War dynamics into the region, reshaping alliances and priorities.

Changes in inter-American dynamics

• Continuation of the Good Neighbour Policy - Initiated in the 1930s by President Roosevelt, this policy aimed to foster non-intervention and mutual respect with Latin America. While wartime cooperation strengthened some ties, post-war US focus on global leadership and anti-communism sometimes strained these principles, leading to interventions in countries perceived as susceptible to Soviet influence.
• Hemispheric solidarity through treaties - The Rio Treaty and OAS formalised collective defence and cooperation, aligning Latin American nations more closely with US strategic goals. These agreements prioritised anti-communist unity, often at the expense of addressing internal inequalities or political grievances in the region.
• Cold War alignments - The emerging US-Soviet rivalry influenced inter-American relations, with the US viewing Latin America as a critical sphere of influence to counter communism. This led to support for anti-communist regimes, even if undemocratic, and set the stage for interventions and proxy conflicts in the region during the Cold War.

These diplomatic shifts highlight how WWII not only elevated the United States to superpower status but also redefined power structures and alliances across the Americas, laying the groundwork for decades of tension and cooperation.