Introduction
Franklin Delano Roosevelt (1882–1945), President of the United States during twelve critical years (1933–1945), not only transformed domestic politics with his New Deal but also redefined the role of the United States on the global stage. His diplomacy, marked by flexible pragmatism, an idealistic vision of international cooperation, and a unique ability to navigate between isolationism and interventionism, laid the foundations for the postwar liberal order. This article explores how FDR combined realpolitik, institutional innovation, and personal leadership to confront the Great Depression, World War II, and the early glimmers of the Cold War, leaving a legacy that continues to shape international relations.

When Franklin Delano Roosevelt assumed the presidency in 1933, the United States was a wounded giant. The Great Depression had shattered not only its economy but also its faith in the future. The country, absorbed in its pain, looked with disdain upon a world sliding into the abyss. But FDR, with his unwavering smile and his brace as a silent witness to his battle with polio, was not a man of inward glances. His vision, as broad as the ocean that surrounded him, understood earlier than anyone that America’s destiny was tied to that of the planet. In twelve years, he transformed a fractured nation into the architect of a new world order, woven with threads of pragmatism, idealism, and a boldness that only history would judge.

The Context: Isolationism, Depression, and the Rise of a New Order
When Roosevelt took office in 1933, the United States was deeply entrenched in isolationism. The trauma of World War I, the failure of the League of Nations, and the protectionism of the Smoot-Hawley Tariff (1930) had distanced the country from global affairs. FDR inherited a nation distrustful of Europe and focused on economic recovery. His challenge was twofold: to revitalize the economy and reposition the U.S. as a global arbiter without provoking internal backlash.

The Diplomacy of the New Deal: Economy as a Global Tool
The New Deal was more than an economic rescue plan: it was the cornerstone of a diplomacy that linked the domestic with the global. While serving soup in public kitchens, Roosevelt was already negotiating in distant halls. At the London Economic Conference (1933), he surprised the world by rejecting agreements that would tie his hands in devaluing the dollar. “Our priority is the American people,” he declared, but behind that statement was a strategy: to rebuild the United States as an economic beacon, even if it meant breaking the rules of the international game.

The New Deal was not just a domestic program; it had international ramifications that FDR skillfully exploited:
a) The London Economic Conference (1933):
In his first year, Roosevelt sent a delegation to London to stabilize currencies and trade. However, in a surprising turn, he rejected agreements that would limit his ability to devalue the dollar, prioritizing domestic recovery over global cooperation. The message was clear: the U.S. would negotiate, but not at the expense of its economic sovereignty.

b) The Good Neighbor Policy (1933):
Roosevelt abandoned interventionism in Latin America, withdrawing troops from Haiti and Nicaragua and annulling the Platt Amendment in Cuba (1934). This shift, more strategic than altruistic, aimed to secure markets for American exports and contain fascist and communist influences.

c) Reciprocal Trade Agreements (1934):
Under the Reciprocal Trade Agreements Act, FDR negotiated bilateral treaties that reduced tariffs, revitalizing trade without requiring Congressional approval. This strategy, although modest, laid the groundwork for subsequent economic multilateralism.

From Neutrality to Belligerence: FDR and the Road to War
By the mid-1930s, as Europe was covered in swastikas and red flags, the United States clung to the myth of invulnerability. The Neutrality Acts (1935–1939) prohibited selling arms to countries at war, but FDR, a master of legal maneuvering, found loopholes. When Spain bled during its civil war, he allowed American trucks labeled as “humanitarian aid” to reach the Republicans. “We are not taking sides,” he said, while clearly taking sides.

The real shift came in 1941 with the Lend-Lease Act. “Imagine your neighbor’s house is on fire,” he argued before Congress. “You wouldn’t sell him a hose; you would lend it to him.” Thus, the United States sent 50,000 tanks, 600,000 trucks, and 12,000 airplanes to Britain, the USSR, and China. It was not neutrality: it was an economic war disguised as generosity.

FDR managed the growing totalitarian threat by balancing public isolationism with military preparation:
a) The Neutrality Acts (1935–1939):
Although he signed these laws (which prohibited selling arms to countries at war), he undermined them through creative interpretations. For example, during the Spanish Civil War (1936–1939), he allowed aid to be sent to the Republicans under the pretext of “non-intervention.”

b) The Lend-Lease Act (1941):
In one of his greatest legislative achievements, FDR convinced Congress to approve the lending of war materials to allies, arguing it was like “lending a hose to a neighbor whose house is on fire.” This program, which sent $50 billion (current value) to Britain, the USSR, and China, was an economic war disguised as neutrality.

c) The Atlantic Charter (1941):
At his secret meeting with Churchill in Newfoundland, FDR outlined principles such as self-determination and freedom of trade. Though idealistic, the document served to unite the Allies under a common cause and pressured the USSR to postpone territorial ambitions.

Wartime Diplomacy: Building the “Grand Alliance”
FDR understood that winning the war required an unlikely coalition:
a) The Soviet Enigma:
Despite distrusting Stalin, FDR prioritized the alliance with the USSR:

• Massive aid: he sent 400,000 trucks and 11,000 planes to the USSR via the Arctic Convoys.
• Key conferences: at Tehran (1943) and Yalta (1945), he conceded in Eastern Europe in exchange for Soviet commitments against Japan and participation in the future UN.

b) Churchill: An Uncomfortable Partner:
Though personally close, FDR and Churchill clashed over:

• Decolonization: FDR pressured to dismantle the British Empire, especially in India.
• Second Front: he insisted on opening the Western Front (D-Day, 1944) to relieve pressure on the USSR, despite British reluctance, particularly due to Winston Churchill’s – accurate – concerns.

c) Chiang Kai-shek’s China: A Symbolic Ally:
FDR elevated China as the “fourth global policeman” in the Moscow Declaration (1943), knowing it was weakened but needing its weight against European colonialism in Asia.

The Art of Embracing the Devil: The Grand Alliance
FDR knew that to defeat Hitler, he needed uncomfortable allies. With Churchill, their relationship was one of shared whiskey and underlying clashes. In Newfoundland, during the Atlantic Charter (1941), they spoke of freedom and self-determination, but FDR was already planning the end of the British Empire. “India cannot remain a colony,” he insisted, while Churchill growled.

With Stalin, the dance was more dangerous. At Tehran (1943) and Yalta (1945), FDR looked the other way regarding Soviet purges, focusing solely on his objective: winning the war. “Stalin is not an idealist like us,” he confessed to an ally. “But he’s the only one with ten million soldiers willing to die.” Thus, he sent 400,000 trucks to the USSR, saving Moscow while condemning Warsaw.

An Institutional Visionary: His Path to a Postwar World
FDR’s great gamble was to create institutions to prevent another global conflict:
a) The United Nations:
Inspired by Woodrow Wilson’s failed League of Nations, FDR designed the United Nations Organization with:

• A Security Council: with veto power for the major powers, ensuring their participation.
• A General Assembly: composed of all countries adhering to the Organization, fulfilling certain requirements, where all could be heard.
• The Bretton Woods Conference (1944): which created the International Monetary Fund and the World Bank, institutionalizing the dollar as the axis of the global economy.

While European cities burned, FDR was already envisioning the postwar world. In 1944, at Bretton Woods, he gathered 44 nations to create the IMF and the World Bank. “The dollar will be the world’s currency,” he announced without blushing. But his masterpiece was the UN: a forum where the powers would guard peace, vetoing conflicts from a Security Council. “This time,” he promised, “we will not repeat Wilson’s mistakes.”

b) Institutionalization of the Morgenthau Plan (1944):
Proposed by his Treasury Secretary, Hans Morgenthau, it sought to deindustrialize Germany, based on a relatively simplistic idea: to prevent the war machine that had fueled two world wars in the 20th century from rising again as a threat. FDR initially supported it but later abandoned it in favor of the reconstructive approach of the Marshall Plan, showing his pragmatism and building a wall of economic prosperity against Stalin’s Red Tide. However, his pragmatism had its shadows. The Morgenthau Plan, proposing to reduce Germany to an agrarian country, briefly tempted him. Later, he opted for reconstruction, planting the seeds of the Marshall Plan. “Punishing the defeated does not bring peace,” he concluded. “It only sows resentment.”

Shadows on the Legacy: Ethics and Contradictions
F.D. Roosevelt’s diplomacy was not free from criticism:

• With the internment of Japanese-Americans (in 1942): considered a racist measure that weakened his image as a champion of human rights.
• Later accusations of indifference toward the Holocaust: he refused to bomb Auschwitz or ease refugee quotas, prioritizing military victory over rescue efforts.
• Deals with dictators: showing absolute pragmatism, from Rafael Leónidas Trujillo in the Dominican Republic to Joseph Stalin, FDR prioritized stability over democracy.

Here we can speak of the scars of power: ethics at a crossroads. FDR’s greatness does not erase his contradictions. In 1942, he signed the order that interned 120,000 Japanese-Americans in camps. “It’s a security measure,” he argued, while his own advisors whispered it was racial paranoia. He also did nothing to save the Jews from the Holocaust: he refused to bomb Auschwitz and maintained strict immigration quotas. “Winning the war is the priority,” he repeated, even at the cost of moral complicity.

The Legacy: The Architecture of a New World
FDR died on April 12, 1945, weeks before the Nazi surrender. However, his institutional vision and idealistic realpolitik shaped much of the rest of the 20th century:

• The hegemonic transition: The U.S. replaced Britain as the global power. A strong decline of the British Empire followed World War II, burdened by the war effort, debts, and an inevitable shift in the times.
• Duality of the Cold War: His alliances with the USSR sowed tensions, but his institutional framework contained the conflict for countless years.
• The dream of interdependence: The United Nations, though an imperfect organization, remains the global forum he envisioned.

The Strategist of the Possible
FDR governed in the era of the possible, not the perfect. His genius was negotiating between ideals and realities, between the isolationism of his people and the demands of a world in flames. As he said in his fourth inaugural address: “We have learned that we cannot live alone, at peace; that our own well-being depends on the well-being of other nations.” In a fractured 21st century, his legacy reminds us that diplomacy is not the art of the perfect, but of the necessary. FDR navigated between shadow and light, between Wilsonian idealism and Kissingerian realism. His greatest lesson: in an imperfect world, the negotiator must be as flexible as he is firm, as visionary as he is grounded.

When FDR died on April 12, 1945, weeks before the fall of Berlin, he left behind a planet fractured but hopeful. His institutions — the UN, the IMF, the World Bank — remain wavering pillars of an order he envisioned. His alliance with Stalin sowed the Cold War, but his faith in multilateral diplomacy prevented a Third World War.
FDR was neither a saint nor a cynic: he was a man who ruled in shades of gray, negotiating with monsters to save what he believed could be saved. In a 21st century where isolationism resurges and institutions falter, his legacy is a reminder: diplomacy is not the art of the perfect, but of the possible. And sometimes, the possible is enough.

The Influence of Illness on His Diplomacy
Franklin Delano Roosevelt’s polio (1921) and his cardiac deterioration by 1944 influenced his decision-making. Some emblematic cases include:

• Yalta (1945): His physical frailty prevented him from resisting Stalin’s push and ambitions over Poland, facilitating the Sovietization of Eastern Europe. At that Conference, the strength of the third actor, Winston Churchill, was also too diminished to impose many conditions.
• Use of intermediaries: He relied on Harry Hopkins and Eleanor Roosevelt for sensitive missions, such as negotiating with Churchill and Soviet leaders. Despite the efforts of these intermediaries, they were not the same as Roosevelt himself, but his physical weakness made it impossible for him to maintain his former vigor.

The Development of So-Called Covert Operations

• The importance of the “Manhattan Project”: FDR authorized the atomic bomb without consulting Congress, negotiating its development in secret with Churchill (at the Quebec Agreement, 1943).
• The development of the OSS (pre-CIA): He created the Office of Strategic Services in 1942, using espionage to influence exiled governments and resistance movements.

FDR and Latin America: Between the Good Neighbor Policy and the Backyard Conception
While promoting non-intervention, FDR tolerated dictatorships like that of Anastasio Somoza in Nicaragua in exchange for support against the Axis. His policy was less idealistic than pragmatic: aiming to secure resources and military bases.
In Latin America, where his predecessors had sent marines, FDR sent respect. The Good Neighbor Policy was not an act of charity, but of cold intelligence: he withdrew troops from Haiti and Nicaragua, abolished the humiliating Platt Amendment in Cuba, and turned dictators like Somoza into discreet allies. “It is better to have friends than colonies,” he seemed to whisper, as U.S. exports flowed into previously closed markets.

In his obsession with stability, he embraced dictators. From Trujillo in the Dominican Republic to Batista in Cuba, he preferred predictable tyrants to chaotic democracies. “They are not angels,” he admitted, “but they are our demons.”