Sphere of influence
A sphere of influence by a country is a foreign geographic region ("sphere") in which that country has trading or investment rights, or more broadly, political or cultural influence.
For example, Britain enjoyed spheres of influence in many regions of the world during the 19th centuries.
Origins
Just as Rome and Carthage competed in the 3rd and 2nd centuries B.C. to control peripheral areas of the western Mediterranean, in the 18th and 19th centuries, Britain, France, and other European imperialist powers competed to divide areas far from home, like India, China, Southeast Asia, and Africa, between them. The initial impulse for these divisions was mercantilist, but they evolved into primarily military contests aimed at geopolitical dominance. They persisted as political demarcations until overwhelmed by World War II and the subsequent end of the colonial era.
The term "sphere of influence" first appeared in the division of Africa at the Berlin Conference (also known as the "Congo Conference") of 1884 – 1885, which apportioned dominance of the continent between Britain, Belgium, France, Germany, Italy, Portugal, and Spain. In 1885, a bilateral agreement between Great Britain and Germany divided control of the Gulf of Guinea between them. Each undertook not to interfere in the interests of the other in its designated sphere. In 1890, the two concluded a similar division of spheres of influence in East Africa.
Western hemisphere
The "Monroe Doctrine" was the first formal declaration of a sphere of influence by any country, though the term itself was not used in diplomacy until 1885. In its original form, it was an effort to deny extra-hemispheric powers spheres of influence that might threaten U.S. security. (The 1904 'Roosevelt Corollary' transformed it from an instrument of strategic denial into an active assertion of U.S. dominance of the Hemisphere.) Proclaimed by U.S. President James Monroe December 2, 1823, on the advice of Secretary of State John Quincy Adams, the Monroe Doctrine demanded the respect of European colonial powers for the independence of states in the Western Hemisphere and declared that any effort on their part to "extend their system to any portion of [the] hemisphere [would be seen] as dangerous to [U.S.] peace and safety." In 1864, as the U.S. was preoccupied with its civil war, France installed Archduke Ferdinand Maximilian Joseph von Hapsburg-Lorraine as the emperor of Mexico. In 1865, with the American Civil War behind it, the U.S. massed 40,000 troops on the Mexican border and demanded that the French remove him. The French withdrew their forces from Mexico. Maximilian was then captured and executed by the forces of Benito Juárez.
The 1904 Roosevelt Corollary to the Monroe Doctrine amended it to proclaim a U.S. right to intervene militarily to correct "flagrant and chronic wrongdoing by a Latin American nation." The U.S. had already seized Cuba and Puerto Rico from Spain, threatened to go to war with Great Britain over Venezuela 1895, and intervened to detach Panama from Colombia in order to build the Panama Canal. It subsequently invaded Nicaragua, Honduras, Mexico, Haiti, the Dominican Republic, Guatemala, Cuba, Panama, Costa Rica, and Grenada and engaged in covert regime change operations in many of these countries as well as in Chile, Venezuela, and Bolivia.
In 1917, a German proposal of an alliance with Mexico helped persuade the United States to enter World War I.
In the 1930s, when Germany and Japan attempted to erode American primacy in countries like Brazil and Peru, the United States tempered its unabashed interventionism by adopting what it called a "Good Neighbor Policy."
Post-World War II
The concept of spheres of influence inspired the organization of the United Nations Security Council, whose permanent members each brought with them dominance of distinct groups of other countries. The General Assembly, by contrast, enshrines the principle of the sovereign equality of states.
In 1942 US President Franklin Roosevelt envisaged a post-World War II world order managed by what he called “the four policemen”, each of which would be responsible for maintaining peace in its sphere of influence. In his conception, Britain would be in charge in its empire and Western Europe, the Soviet Union in eastern Europe and the central Eurasian landmass, China in East Asia and the western Pacific, and the United States in the Western Hemisphere. At the insistence of British Prime Minister Winston Churchill, France was later added and recognized as responsible for the affairs of its empire.