5. United Kingdom
> Number of US installations: 18
> Total size and value of installations: 18,456 acres; $13.0 billion
> Largest US base in United Kingdom: Naval Support Facility Diego Garcia (nearest city: N/A)
> United Kingdom’s military spending in 2019: $48.65 billion (1.7% of GDP)
> GDP per capita: $46,330.34
> Population: 66.5 million
There are 18 major military installations in the United Kingdom — the largest of which is the 7,000-acre Naval base located in the British overseas territory of Diego Garcia. The second largest U.S. base in Great Britain is the Ascension Auxiliary Airfield, which is also located off the mainland in the territory of St. Helena. The U.S. Air Force shares this base with the Royal Air Force. The largest American base on the mainland is the RAF Lakenheath, which is home to the 48th Fighter Wing.
> Number of US installations: 29
> Total size and value of installations: 2,313 acres; $9.5 billion
> Largest US base in Italy: Aviano Air Base (nearest city: Aviano)
> Italy’s military spending in 2019: $26.79 billion (1.4% of GDP)
> GDP per capita: $42,188.51
> Population: 60.4 million
Italy is one of several U.S. adversaries from WWII that are now a close ally — and home to multiple American military installations. The country is home to nine major Air Force installations, 10 Army installations, and another 10 Navy installations. The largest U.S. base in the country is the Aviano Air Base, located in northern Italy and home to the 31st Fighter Wing. The second largest U.S. base in the country is the Naval Air Station Sigonella in Sicily, which is part of a larger NATO base that includes troops from other member states.
3. South Korea
> Number of US installations: 64
> Total size and value of installations: 30,944 acres; $24.4 billion
> Largest US base in South Korea: Pyeongtaek Cpx Area (nearest city: Pyeongtaek)
> South Korea’s military spending in 2019: $43.89 billion (2.7% of GDP)
> GDP per capita: $39,492.27
> Population: 51.6 million
South Korea is a close U.S. ally that shares a border with one of our nation’s most dangerous adversaries — North Korea, a nuclear power. As of September 2020, the U.S. had 64 major bases throughout the country, operated by the Army, Navy, Air Force, and Marine Corps.
Recently, Camp Humphreys in Pyeongtaek, about an hour south of the South Korean capital of Seoul, underwent a massive expansion. Once one of the smaller installations in the country, the base recently tripled in size from housing about 11,000 U.S. troops to over 40,000. The base is a focal point of U.S. operations in Asia.
> Number of US installations: 86
> Total size and value of installations: 114,919 acres; $98.1 billion
> Largest US base in Japan: Camp Fuji (nearest city: Fuji)
> Japan’s military spending in 2019: $47.61 billion (0.9% of GDP)
> GDP per capita: $41,205.96
> Population: 126.5 million
As of September 2017, Japan was host to 86 major American military installations — the most of any country in Asia and second most in the world, not counting the United States. The largest U.S. installation in the country is Camp Fuji, which contains five live fire ranges and is operated by the Marine Corps. The camp is located on the main island of Honshu less than two hours from Tokyo. The U.S.-Japan military alliance is a pillar of stability in the region.
The concentration of American military installations in Japan are due in large part to an agreement forged in 1960. The U.S.-Japan agreement allowed the United States to establish bases in the country — giving the U.S. a foothold in Asia — so long as it defended Japan if it were attacked.
> Number of US installations: 87
> Total size and value of installations: 6,373 acres; $44.7 billion
> Largest US base in Germany: Ramstein Air Base (nearest city: Ramstein)
> Germany’s military spending in 2019: $49.28 billion (1.3% of GDP)
> GDP per capita: $53,659.99
> Population: 82.9 million
Germany, one of the closest U.S. allies today, is host to 87 major American military installations — the largest of which by total acreage is the Ramstein Air Base. In close proximity to the borders of nine other countries, the base serves as the U.S. Air Force European headquarters and is sometimes referred to as “Little America” because of the tens of thousands of U.S. personnel in the area. The second largest US installation in the country is the Spangdahlem Air Base, located in western Germany. The base is home to the 52nd Fighter Wing.
The world-leading U.S. military presence in Germany can be partially explained by the two country’s history since the end of World War II, when the U.S. military was part of the decade-long occupation of Germany. The U.S. European Command is headquartered in Stuttgart, Germany.