For better or for worse, the United States has been described as the self-appointed police force of the world by politicians and pundits alike. Like any good police force, the US has plenty of stations to dispatch officers from. Only, in this case, those stations are all over the globe and known as overseas American military bases.
It’s become accepted that there are US military bases around the world, but rarely does one stop to ask exactly how the US even has military bases in other countries in the first place. The story is a mixture of diplomatic relationships, international alliances, and good ol' fashioned American military dominance.
The historical reasons for US military bases abroad are as varied as the bases themselves. Sometimes, the US is helping an ally out with training and defense. Other times, they’re keeping an eye on a recently defeated enemy. Bizarrely, they sometimes even hold their worst political enemies in an illegal detention facility in a country they have next to no diplomatic ties to. The basic rule of thumb is this: if the US could benefit from having a military base in a certain location, they’ve probably already got one there.
Even Local Constitutions Can't Stop The US From Building Bases
Some foreign countries have constitutions and charters that outright ban other nations from establishing bases of any sort on their soil. However, if local politicians are willing to play ball, chances are the United States can figure out a way to maintain a military presence there.
The roster of US military “bases” around the world includes several informal and unofficial locations, including a number of military "golf courses." This avoids outright breaking local laws, and still allows the US to keep an eye on things.
The US Snagged A Bunch Of Territory After WWII
The concept of creating and maintaining foreign military bases is something that has only really become a "thing" in the post-World War Two era. This is because before WWII, the same goals and purposes of foreign military bases were accomplished through colonialism.
This is important, because it meant that America was one of the few nations that was even capable of setting up such an international system. WWII devastated all of Europe, leaving America, a late entrant into the war, as the sole remaining superpower. The Soviets would soon join them, but not before the Americans had already begun peppering the world with bases.
The US Typically Sets Up Shop After Defeating An Enemy
World War Two provided a new sort of military base-creating opportunity for the United States. This came from those nations that were defeated by the sudden superpower that was the USA. Germany, Japan, and Italy were all forced to accept permanent installations from the victorious Americans.
They generally welcomed the US at the time due to their also mandatory pro-American post-war governments. America used the old excuse of "stabilizing" the war-torn regions as justification for the semi-occupations.
American Troops Basically ARE The Japanese Military
Japan, the last hostile power to surrender to the USA in World War II, suffered the toughest sanctions in their eventual surrender agreement. The treaty struck between the two countries included a total ban on Japan maintaining any sort of future military, although an exception was later made for homeland security.
This leaves Japan at the mercy of American protection, a status they hold to this day. This obviously requires several US military bases on Japanese soil, to "maintain peace."