Superpower in the context of "Post–World War II"

In international relations, power is defined in several different ways. Material definitions of state power emphasize economic and military power. Other definitions of power emphasize the ability to structure and constitute the nature of social relations between actors. Power is an attribute of particular actors in their interactions, as well as a social process that constitutes the social identities and capacities of actors.

International relations scholars use the term polarity to describe the distribution of power in the international system. Unipolarity refers to an international system characterized by one hegemon (e.g. the United States in the post–Cold War era), bipolarity to an order with two great powers or blocs of states (e.g. the Cold War), and multipolarity refers to the presence of three or more great powers. Those states that have significant amounts of power within the international system are referred to as small powers, middle powers, regional powers, great powers, superpowers, or hegemons, although there is no commonly accepted standard for what defines a powerful state.

Russia, or the Russian Federation, is a country in Eastern Europe and North Asia. It is the largest country in the world, spanning eleven time zones and sharing land borders with fourteen countries. With a population of over 140 million, Russia is the most populous country in Europe and the ninth-most populous country in the world. It is a highly urbanised country, with sixteen of its urban areas having more than 1 million inhabitants. Moscow, the most populous metropolitan area in Europe, is the capital and largest city of Russia; and Saint Petersburg is its second-largest city and cultural centre.

Human settlement on the territory of modern Russia dates back to the Lower Paleolithic. The East Slavs emerged as a recognised group in Europe between the 3rd and 8th centuries AD. The first East Slavic state, Kievan Rus', arose in the 9th century, and in 988, it adopted Orthodox Christianity from the Byzantine Empire. Kievan Rus' ultimately disintegrated; the Grand Duchy of Moscow led the unification of Russian lands, leading to the proclamation of the Tsardom of Russia in 1547. By the early 18th century, Russia had vastly expanded through conquest, annexation, and the efforts of Russian explorers, developing into the Russian Empire, which remains the third-largest empire in history. However, with the Russian Revolution in 1917, Russia's monarchic rule was abolished and eventually replaced by the Russian SFSR—the world's first constitutionally socialist state. Following the Russian Civil War, the Russian SFSR established the Soviet Union with three other Soviet republics, within which it was the largest and principal constituent. The Soviet Union underwent rapid industrialisation in the 1930s, amidst the deaths of millions under Joseph Stalin's rule, and later played a decisive role for the Allies in World War II by leading large-scale efforts on the Eastern Front—rising as a global superpower. With the onset of the Cold War, it competed with the United States for ideological dominance and international influence. The Soviet era of the 20th century saw some of the most significant Russian technological achievements, including the first human-made satellite and the first human expedition into outer space.

The revolutions of 1989, also known as the fall of communism, were a wave of liberal democratic movements that resulted in the collapse of most Marxist–Leninist governments in the Eastern Bloc and other parts of the world. This wave is sometimes referred to as the "autumn of nations", in reference to the revolutions of 1848 as the "spring of nations". The revolutions of 1989 were a key factor in the dissolution of the Soviet Union—one of the two superpowers—and abandonment of communist regimes in many parts of the world, some of which were violently overthrown. These events drastically altered the world's balance of power, marking the end of the Cold War and beginning of the post-Cold War era.

The earliest recorded protests, which led to the revolutions, began in Poland on 14 August 1980, the massive general strike which led to the August Agreements and establishment of Solidarity, the first and only independent trade union in the Eastern Bloc, whose peak membership reached 10 million. The main region of the 1989 revolutions was Central Europe, starting in Poland with the 1988 Polish strikes, and continued in Hungary, East Germany, Bulgaria, Czechoslovakia, and Romania. On 4 June 1989, Poland conducted the first elections that led to the dissolution of the communist government, with Solidarity winning an overwhelming victory, leading to the peaceful fall of communism in Poland. Influenced by Poland, Hungary organised round table-format talks and began dismantling its section of the Iron Curtain. In August 1989, over a quarter of the Baltic states population physically chained for 675 kilometres (419 mi) in the Baltic Way protesting the occupation by the Soviet Union, while the opening of a border gate between Austria and Hungary set in motion a peaceful chain reaction, in which the Eastern Bloc disintegrated. This led to mass demonstrations in cities of East Germany and the fall of the Berlin Wall in November 1989, which served as the symbolic gateway to German reunification in 1990. A feature common to these developments was the extensive use of campaigns of civil resistance, demonstrating popular opposition to the continuation of one-party rule and contributing to pressure for change. Romania was the only country in which citizens and opposition forces used violence to overthrow its communist regime, although Romania was politically isolated from the rest of the Eastern Bloc.

The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 states and a federal capital district, Washington, D.C. The 48 contiguous states border Canada to the north and Mexico to the south, with the semi-exclave of Alaska in the northwest and the archipelago of Hawaii in the Pacific Ocean. The United States also asserts sovereignty over five major island territories and various uninhabited islands in Oceania and the Caribbean. It is a megadiverse country, with the world's third-largest land area and third-largest population, exceeding 340 million.

Paleo-Indians first migrated from North Asia to North America over 12,000 years ago, and formed various civilizations. Spanish colonization established Spanish Florida in 1513, the first European colony in what is now the continental United States. British colonization followed with the 1607 settlement of Virginia, the first of the Thirteen Colonies. Enslavement of Africans was practiced in all colonies by 1770 and supplied most of the labor for the Southern Colonies' plantation economy. Clashes with the British Crown over taxation and lack of parliamentary representation sparked the American Revolution, leading to the Declaration of Independence on July 4, 1776. Victory in the 1775–1783 Revolutionary War brought international recognition of U.S. sovereignty and fueled westward expansion, dispossessing native inhabitants. As more states were admitted, a North–South division over slavery led the Confederate States of America to attempt secession and fight the Union in the 1861–1865 American Civil War. With the United States' victory and reunification, slavery was abolished nationally. By 1900, the country had established itself as a great power, a status solidified after its involvement in World War I. Following Japan's attack on Pearl Harbor in 1941, the U.S. entered World War II. Its aftermath left the U.S. and the Soviet Union as rival superpowers, competing for ideological dominance and international influence during the Cold War. The Soviet Union's collapse in 1991 ended the Cold War, leaving the U.S. as the world's sole superpower.

The president of the United States (POTUS) is the head of state and head of government of the United States. The president directs the executive branch of the federal government and is the commander-in-chief of the United States Armed Forces.

The power of the presidency has grown since the first president, George Washington, took office in 1789. While presidential power has ebbed and flowed over time, the presidency has played an increasing role in American political life since the beginning of the 20th century, carrying over into the 21st century with some expansions during the presidencies of Franklin D. Roosevelt and George W. Bush. In the 21st century, the president is one of the world's most powerful political figures and the leader of the world's only remaining superpower. As the leader of the nation with the largest economy by nominal GDP, the president possesses significant domestic and international hard and soft power. For much of the 20th century, especially during the Cold War, the U.S. president was often called "the leader of the free world".

The Cold War was a period of global geopolitical rivalry between the United States (US) and the Soviet Union (USSR) and their respective allies, the capitalist Western Bloc and communist Eastern Bloc, which began in the aftermath of the Second World War and ended with the dissolution of the Soviet Union in 1991. The term cold war is used because there was no direct fighting between the two superpowers, though each supported opposing sides in regional conflicts known as proxy wars. In addition to the struggle for ideological and economic influence and an arms race in both conventional and nuclear weapons, the Cold War was expressed through technological rivalries such as the Space Race, espionage, propaganda campaigns, embargoes, and sports diplomacy.

After the end of the Second World War in 1945, during which the US and USSR had been allies, the USSR installed satellite governments in its occupied territories in Eastern Europe and North Korea by 1949, resulting in the political division of Europe (and Germany) by an "Iron Curtain". The USSR tested its first nuclear weapon in 1949, four years after their use by the US on Hiroshima and Nagasaki, and allied with the People's Republic of China, founded in 1949. The US declared the Truman Doctrine of "containment" of communism in 1947, launched the Marshall Plan in 1948 to assist Western Europe's economic recovery, and founded the NATO military alliance in 1949 (matched by the Soviet-led Warsaw Pact in 1955). The Berlin Blockade of 1948 to 1949 was an early confrontation, as was the Korean War of 1950 to 1953, which ended in a stalemate.

The post–Cold War era is a period of history that follows the end of the Cold War, which represents history after the dissolution of the Soviet Union in December 1991. This period saw many former Soviet republics become sovereign states, as well as the introduction of market economies in Eastern Europe. This period also marked the United States becoming the world's sole superpower.

Relative to the Cold War, the period is characterized by stabilization and disarmament. Both the United States and Russia significantly reduced their nuclear stockpiles. Much of the former Eastern Bloc became democratic and was integrated into the world economy. In the first two decades of the period, NATO underwent three enlargements, and France reintegrated into the NATO command. Russia formed the Collective Security Treaty Organization to replace the dissolved Warsaw Pact, established a strategic partnership with China and several other countries, and entered the Shanghai Cooperation Organisation and BRICS alongside China, which is a rising power. Reacting to the rise of China, the United States began a gradual rebalancing of strategic forces to the Asia–Pacific region and out of Europe.

The Union of Soviet Socialist Republics (USSR), commonly known as the Soviet Union, was a transcontinental country that spanned much of Eurasia from 1922 until it dissolved in 1991. During its existence, it was the largest country by area, extending across eleven time zones and sharing borders with twelve countries, and the third-most populous country. An overall successor to the Russian Empire, it was nominally organized as a federal union of national republics, the largest and most populous of which was the Russian SFSR. In practice, its government and economy were highly centralized. As a one-party state governed by the Communist Party of the Soviet Union (CPSU), it was the flagship communist state. Its capital and largest city was Moscow.

The Soviet Union's roots lay in the October Revolution of 1917. The new government, led by Vladimir Lenin, established the Russian SFSR, the world's first constitutionally communist state. The revolution was not accepted by all within the Russian Republic, resulting in the Russian Civil War. The Russian SFSR and its subordinate republics were merged into the Soviet Union in 1922. Following Lenin's death in 1924, Joseph Stalin came to power, inaugurating rapid industrialization and forced collectivization that led to significant economic growth but contributed to a famine between 1930 and 1933 that killed millions. The Soviet forced labour camp system of the Gulag was expanded. During the late 1930s, Stalin's government conducted the Great Purge to remove opponents, resulting in large scale deportations, arrests, and show trials accompanied by public fear. Having failed to build an anti-Nazi coalition in Europe, the Soviet Union signed a non-aggression pact with Nazi Germany in 1939. Despite this, in 1941 Germany invaded the Soviet Union in the largest land invasion in history, opening the Eastern Front of World War II. The Soviets played a decisive role in defeating the Axis powers while liberating much of Central and Eastern Europe. However they would suffer an estimated 27 million casualties, which accounted for most losses among the victorious Allies. In the aftermath of the war, the Soviet Union consolidated the territory occupied by the Red Army, forming satellite states, and undertook rapid economic development which cemented its status as a superpower.