United States

The United States declared independence from Britain in 1776, secured recognition through the Treaty of Paris in 1783, and has since expanded from thirteen Atlantic seaboard colonies into a continental republic of fifty states with overseas territories spanning the Pacific and Caribbean. The Civil War of 1861–65 settled by force what the Constitution had left unresolved — whether the Union was voluntary — and the Great Depression of the 1930s forced a wholesale renegotiation of the relationship between federal government and market. Both crises produced durable institutional settlements: the Fourteenth Amendment and the New Deal administrative state, respectively. Victory in two world wars and the Soviet Union's dissolution in 1991 left Washington the singular architect of the postwar international order.

That order runs through American institutions in ways that no rival has yet replicated. The Federal Reserve sets the effective floor for global liquidity. The U.S. Indo-Pacific Command projects force across half the earth's surface. The dollar underwrites roughly 58 percent of global foreign exchange reserves. Congress, the presidency, and a Supreme Court with lifetime appointments share power under a constitution ratified in 1789 — the oldest written national charter still in operation. The United States enters 2025 as the world's largest economy by nominal GDP, its most capable military power, and the state whose domestic political choices carry the heaviest external consequences for every other entry in this dossier.

The contiguous United States occupies 9,833,517 square kilometres of North American landmass — land area of 9,147,593 square kilometres, water of 685,924 square kilometres — making it slightly larger than China and more than twice the size of the European Union, though only half the size of Russia. Geographic coordinates centre near 38°N, 97°W, a point in the southern Great Plains that conveys the country's essential midcontinental character. Two land borders define its terrestrial limits: 8,891 kilometres shared with Canada (including 2,475 kilometres along Alaska's perimeter) and 3,111 kilometres shared with Mexico, for a combined boundary total of 12,002 kilometres. The coastline extends 19,924 kilometres, with maritime claims reaching 12 nautical miles of territorial sea, a 24-nautical-mile contiguous zone, and a 200-nautical-mile exclusive economic zone.

Terrain organises itself into three broad belts. A vast central plain dominates the interior. The west rises into major mountain systems; the east offers hills and low mountains of older, eroded stock; Alaska presents rugged terrain and broad river valleys; Hawaii, volcanic and oceanic, stands apart in every respect. Elevation range is extraordinary. Death Valley sits at -86 metres, the lowest point in North America. Mount McKinley — also called Denali — peaks at 6,190 metres, the highest point on the continent and, measured from base to summit, a mile taller in relief than Everest itself. McKinley's subarctic position at 63°N generates some of the coldest and most violent mountain weather recorded anywhere, with temperatures reaching -93°F and winds exceeding 150 miles per hour. Hawaii's Mauna Kea, rising approximately 10,200 metres from the Pacific Ocean floor to its 4,207-metre summit, is measurably the world's tallest mountain by that metric, though it crests well below sea-level baseline comparisons favour for Everest.

Climate spans the full spectrum. The lower 48 states are mostly temperate. Florida and Hawaii carry tropical conditions. Alaska grades into arctic. The Great Plains west of the Mississippi trend semiarid; the Great Basin of the Southwest is arid. Winter temperatures in the northwest moderate intermittently through chinook winds descending the eastern Rocky Mountain slopes in January and February — a local phenomenon with outsized agricultural consequence.

Land use reflects the country's productive scale: 46.1 percent of territory classified as agricultural land (2023 estimate), of which 16.6 percent is arable and 29.2 percent permanent pasture; forest covers 33.8 percent. Irrigated land reached 234,782 square kilometres as of 2017. Five major aquifer systems underpin agricultural and municipal water supply — the Ogallala (High Plains), the California Central Valley system, the Northern Great Plains, the Cambrian-Ordovician system, and the Atlantic and Gulf Coastal Plains aquifer. Surface hydrology is anchored by the Missouri (3,768 km), the Mississippi (3,544 km), the Yukon, the Saint Lawrence, and the Rio Grande; the Mississippi watershed alone drains 3,202,185 square kilometres into the Gulf of America. Lake Michigan at 57,750 square kilometres is the largest lake lying entirely within U.S. waters.

Natural hazards are geographically distributed rather than concentrated. Hurricanes threaten the Atlantic and Gulf coasts; tornadoes the Midwest and Southeast; earthquakes the Pacific Basin rim; volcanic activity clusters in Hawaii, Western Alaska, the Aleutian Arc, and the Pacific Northwest. Pavlof in Alaska's Aleutian Arc poses documented risk to intercontinental air routes. Mount St. Helens, whose 1980 eruption remains a benchmark event in modern volcanology, is still active. Natural resources are correspondingly extensive: the country holds 491 billion short tons of coal — 27 percent of world reserves — alongside petroleum, natural gas, timber, copper, rare earth elements, uranium, and substantial arable land.

The United States operates as a constitutional federal republic, a form codified in the Constitution ratified across the original thirteen states by 21 June 1788 and effective 4 March 1789 — the successor document to the Articles of Confederation and Perpetual Union of 1781. Sovereignty is distributed across three coequal branches at the federal level and replicated, with variation, across 50 states and the District of Columbia. Washington, D.C., named for the republic's first president, serves as the capital.

The Constitution itself is deliberately resistant to revision. Amendment requires a joint resolution passed by two-thirds majorities in both chambers of Congress, or a constitutional convention convened at the request of two-thirds of state legislatures, followed by ratification from three-fourths of states. The President holds no formal role in this process — a structural separation that distinguishes American constitutional design from most parliamentary systems.

Legislative authority rests in a bicameral Congress. The Senate comprises 100 seats, each member directly elected to a six-year term on a staggered renewal schedule; women currently hold 26 percent of seats. The House of Representatives holds 435 voting seats renewed in full every two years, with six additional non-voting delegates representing the District of Columbia and five territories. Following the November 2024 elections, Republicans hold 220 House seats to Democrats' 215, and Republicans secured a net gain of 15 Senate seats in the cycle against Democrats' 19 contested. Six registered parties hold varying degrees of national presence, though the Republican and Democratic parties monopolise federal legislative representation.

The legal system operates on English common law at the federal level, extended through 50 state jurisdictions — Louisiana alone diverging, its state law grounded in Napoleonic civil code, a legacy of French colonial governance. Judicial review of legislative acts is a standing feature of the system. Universal suffrage applies at 18 years of age.

The United States withdrew acceptance of compulsory ICJ jurisdiction in 2005 and withdrew acceptance of ICC jurisdiction in 2002, positions that define its posture toward international legal mechanisms. Citizenship is available by birth and by descent; dual citizenship is not formally recognised, though the government acknowledges its de facto occurrence. Naturalisation requires five years of residency. Beyond the 50 states, the United States administers 14 dependent territories, including Puerto Rico, Guam, and the Virgin Islands, alongside free-association relationships with the Marshall Islands, the Federated States of Micronesia, and Palau — arrangements that trace directly to the dissolution of the U.S.-administered Trust Territory of the Pacific Islands between 1986 and 1994.

The United States economy registered a nominal GDP of $29.185 trillion at official exchange rates in 2024, making it the largest national economy in the world by that measure. Real GDP in purchasing-power-parity terms reached $25.676 trillion in 2024 dollars, with real growth of 2.8 percent — the third consecutive year of expansion above 2.5 percent. Real GDP per capita stood at $75,500, a figure that places American household output well above peer high-income economies. The structural driver is services, which contributed 79.7 percent of GDP by sector in 2024; industry accounted for 17.3 percent and agriculture for 0.9 percent. Within the expenditure breakdown, household consumption supplied 67.9 percent of output, with government consumption adding a further 13.4 percent and fixed-capital investment 21.6 percent.

The labor force numbered 174.174 million in 2024. Unemployment stood at 4.2 percent, up from 3.7 percent in each of the two preceding years, with youth unemployment reaching 9.4 percent — 10.4 percent for males and 8.3 percent for females. Consumer price inflation decelerated sharply, falling to 2.9 percent in 2024 from 4.1 percent in 2023 and a peak of 8.0 percent in 2022, the highest rate recorded in that series since the early-1980s tightening cycle.

The fiscal position is structurally imbalanced. Federal revenues reached $4.877 trillion in 2023 against expenditures of $6.857 trillion, producing a deficit of roughly $1.98 trillion. Central government tax revenues represent only 10.6 percent of GDP, an unusually low ratio for an advanced economy of this scale. Public debt had reached 114.8 percent of GDP by end-2023. Reserves of foreign exchange and gold totalled $910.037 billion in 2024, up from $773.426 billion the year before.

Trade flows are large and persistently imbalanced. Exports of goods and services totalled $3.191 trillion in 2024; imports reached $4.108 trillion, producing a current account deficit of $1.134 trillion — wider than the $905 billion recorded in 2023 and comparable to the $1.012 trillion deficit of 2022. The top export commodities are crude petroleum, refined petroleum, natural gas, gas turbines, and cars; Canada and Mexico together absorb 27 percent of exports, with China at 8 percent and Germany and Japan at 5 and 4 percent respectively. On the import side, Mexico and China each supplied 15 percent of the total, Canada 14 percent. Cars, crude petroleum, broadcasting equipment, computers, and garments lead import categories. The dollar's global reserve role is structural: nine jurisdictions use it as their sole legal tender, and four more accept it alongside domestic currency.

Income distribution reflects persistent concentration. The Gini index registered 41.8 in 2023, with the top income decile capturing 30.4 percent of household income against 1.8 percent for the lowest decile. American households allocate 6.8 percent of expenditure to food and 1.9 percent to alcohol and tobacco. The industrial base, second-largest in the world by output, spans petroleum, steel, motor vehicles, aerospace, telecommunications, chemicals, and electronics — a breadth that no peer economy yet matches in aggregate.

The United States fields approximately 1.28 million active-duty personnel across five military branches: the Army at 450,000, the Navy at 334,000, the Air Force at 317,000, the Marine Corps at 168,000, and the Space Force at 10,000. The Coast Guard contributes a further 42,000. Of that total uniformed force, roughly 200,000 are deployed overseas at any given time on either permanent basing or long-term rotational assignments typically running three to nine months — a posture that distributes American military presence across every major theatre simultaneously.

Defence expenditure has held near 3.2 percent of GDP from 2022 through 2025, a figure that represents a modest contraction from the 3.5 percent recorded in 2021. The plateau reflects a force structure whose underlying scale remains unchanged even as the headline percentage edged down. At an economy of this size, 3.2 percent of GDP translates to a defence budget that exceeds the combined total of the next several major military spenders.

The force is entirely volunteer, a structure in place since 1973, though the Selective Service System continues to require registration from males aged 18 to 25 — a legislative backstop that Congress can activate in a declared national emergency without structural modification. Enlistment opens at age 17 with parental consent, and initial service obligations run eight years, of which two to five are served on active duty depending on the branch. Women have access to all military occupations and positions; as of 2023 they comprised 17.7 percent of total regular military personnel. Non-citizens residing legally and permanently in the United States may enlist as long as they hold work authorisation, a high school diploma, and English fluency. Citizens of the Federated States of Micronesia, the Republic of Palau, and the Republic of the Marshall Islands — parties to the Compact of Free Association — may volunteer without additional qualification.

The breadth of eligible personnel categories reflects a recruitment architecture calibrated to sustain a globally deployed all-volunteer force at scale. One hundred and eighty thousand active-duty soldiers and sailors stationed abroad at any moment is a structural commitment, not an operational surge.