The 20th century was one of the affirmation of American power on the world stage and even, from 1945, of the progressive establishment of its hegemony in the context of the Cold War.

The foundations of the foreign policy of the United States

Independent from the British Crown since the Declaration of Independence of July 4, 1776, the United States (US) appears, compared to the "old continent", as a "new country" that has long preferred to prosper within its protective borders rather than risk the adventure on too large a scale. In 1823, the Monroe Doctrine (named after the fifth president of the United States) established for several decades the attitude that the United States intended to adopt towards a European continent that was still dominant in the world. The idea was to delimit spheres of influence: the United States undertook not to deal with European affairs on condition that Europeans would do the same on the American continent. However, since the birth of the American nation, a messianic discourse of universalist scope has been developing, the sacralization of democratic and liberal principles thought to be the foundations of an exportable model. In 1845, the New York journalist John O'Sullivan evoked the "manifest destiny" weighing on American politics, supposedly guided by divine providence. Although the expression was initially used strictly internally to justify the colonization of Indian lands and the conquest of the West, it was used again throughout the 19th and 20th centuries to justify the growing interventions of the United States in the world.

The 2nd World War and the end of isolationism

The outbreak of the 2nd World War requires the country to gradually commit itself to the Allied forces. In March 1941, the US passed the "Lend-Lease" law authorising the President to "sell, transfer, exchange, lease or otherwise provide" war material and all other goods to the States fighting against the Axis powers. The country becomes the "Arsenal of Democracies" without engaging directly in the conflict. Roosevelt is also part of the tradition and legacy of Wilson (and his famous "14 points" of 1918): from the beginning of the Second World War, he set out in the Atlantic Charter (1941) the fundamental principles of a new world order (collective security, the right of peoples to self-determination, democracy, freedom of trade, etc.). The surprise attack by the Japanese on the Pearl Harbor base on 7 December 1941 tipped the country into war. In January 1942, Roosevelt launched the Victory Program to support the war effort. Isolationism lived.

The role and place of the United States in the world since 1945

The question then becomes how US foreign policy has evolved since 1918: What role does the US intend to play on the international stage since the end of the First World War? How has American power manifested itself in the world since 1945? What are the foundations and the stakes of their interventionism? This reflection on the evolution of US international policy must obviously take into account the different actors involved in the decision-making process:
  • The White House, which, as an "imperial presidency" (a concept coined by the historian Arthur M. Schlesinger, Jr., which evokes an institutional imbalance linked to the fact that the executive branch, in particular the president, tends to attribute more power than it should, especially in foreign policy), plays a central role, both under the Republicans and the Democrats (even if the differences between the two are notable). To this must be added the personal advisers of successive presidents.
  • The Pentagon, which houses the headquarters of the Department of Defense, and what Einsenhower will call in the late 1950s the military-industrial complex
  • The Congress, jealous of the principle of the separation of powers and constitutionally responsible for ratifying international treaties and voting on military credits
  • The CIA (Central Intelligence Agency) created in 1947 at the beginning of the Cold War, very active in the defence of national interests.
  • The Secretariats of Defence and the Treasury.
  • Private institutional actors such as the FTN, the Hollywood studios, the lobbies...
  • Public opinion, largely shaped by the mass media and in which the different immigrant communities weigh in.
 

 1945-1947: THE UNITED STATES, A VICTORIOUS AND AMBITIOUS POWER.

The United States, the great victors of World War II

The US emerges as the great victors of the 2nd World War and quickly establishes itself as a superpower that cannot be ignored. Their superiority is undeniable in all fields: They enjoy immense prestige in the world for their fight against fascism and totalitarianism and are seen as saviors and liberators. The United States and its ideological model (liberal capitalism, consumer society, opulence...) fascinate the world and exert an incomparable attraction. They largely dominate the world economy: their territory has not suffered from the war and their productive capacities have even been increased by the Victory Program. In 1945, they thus held 2/3 of the world's gold stock and represented approximately ½ of the world's industrial production. Finally, they have an undeniable military superiority: their troops are present on the former battlefields of the war, such as in Germany and in the Pacific (in particular in Japan) and their arsenal is much larger than that of the other powers. Above all, they are the only ones to possess the atomic weapon...

The US and the bases of a new world.

In the aftermath of the 2nd World War, the world has to be rebuilt, materially as well as economically and politically. In this context, the US will now seek to establish a world order based on the central principles of its ideological model: democracy and liberal capitalism. As early as 1944, F.D. Roosevelt clearly expressed his desire to build a new world at the Inter-Allied Conferences: - In July 1944 at Bretton Woods: the conference leads to the creation of the IMF, the World Bank and the consecration of the dollar as the international reference currency (national currencies are indexed to the US currency and the latter is itself indexed to gold). The American world economy is being established. - On June 26, 1945 in San Francisco where the United Nations Charter is adopted, based on the Atlantic Charter of 1941. After the failure of the League of Nations, Roosevelt realizes the Wilsonian dream of world peace based on the principle of collective security. The headquarters of the United Nations was established in New York in 1946... During the Yalta and Potsdam conferences (in February and August 1945), the Allies (English, Soviet and American) agreed as best they could on the fate of the defeated and on the political reorganization of the world (in particular on the modalities of restoring democracy in the liberated territories)... They organized and participated in the Nuremberg (1945-46) and Tokyo (1946-48) trials of Nazi and Japanese officials. It was in the context of these trials that the legal concept of "crime against humanity" emerged. Americans and Soviets, haloed with the prestige of victory and seeking to disseminate (or even impose) their respective ideological models, are rapidly competing on a global scale. In 1946, Churchill speaks of the establishment of an "iron curtain" over Europe and George Kennan (American diplomat posted in Moscow) denounced the diplomatic manoeuvres of the USSR and expressed the need for his country to lead a "new crusade for freedom". The "great alliance" of the Second World War is definitively broken. The Cold War begins...