字幕表 動画を再生する 英語字幕をプリント This video was made possible by Brilliant. Learn complex topics simply with Brilliant for 20% off by being one of the first 200 to sign up at brilliant.org/Wendover. If you ask the US military how many bases they have overseas, you won't really get an answer. They don't make it all too hard to find out about the larger ones—Ramstein Air Base in Germany, Thule Air Base in Greenland, Camp Hansen in Japan. These all show up on the closest thing to an official catalogue of the US military's real estate there is—the annual Department of Defence Base Structure Report. According to this document the American military has some 514 sites outside of its borders, but, there are some noticeable omissions to this list. For example, the US has a rather secretive drone base in central Niger, however, according to this list, it doesn't exist. The US has more than ten sites in Syria, however, according to this list, they don't exist. The US has a satellite surveillance facility in Australia's Northern Territory so well known, in fact, that it has a whole fictional TV show based on it, but, according to this list, it doesn't exist. In fact, according to this list, there are just four defense department installations in Africa—a base in Djibouti, a joint British-American base on Ascension Island, an NSA site in Kenya, and a Naval Medical Research facility in Egypt. Of course, if you dig a little deeper into the vast archive of unclassified military documents, you find this—a slide from a presentation clearly showing 34 US military sites in Africa. With omissions such as these, one can assume that that total 514 number is far from the real count of how many facilities the US military maintains abroad. Part of this could be attributed to the fact that it's sometimes tough to define what a military base is. Again looking at the African continent, the only site that looks like what most would traditionally think of as an overseas military base is Camp Lemonnier in Djibouti. It is the only permanent, exclusive US military site, at least according to their own definition, on the continent, hosts about 4,000 members of the US military at a time, and is the primary base of operations for the US Africa Command. You see, the US military splits the world into six regions each with their own infrastructure of bases. Each has a hierarchy of sites. The highest, in the case of Africa Command, are those permanent, full-blown bases—the one in Djibouti and the one on Ascension Island. One step below that are what are called Cooperative Security Locations. These are, according to the US military's definition, “host-nation [facilities] with little or no permanent U.S. personnel presence, which may contain pre-positioned equipment and/or logistical arrangements and serve both for security cooperation activities and contingency access.” CSL's are useful to the US military because they are much less flashy and less permanent—they don't require the same kind of political capital as to set up as a full-size base like the one in Djibouti. Bases are often unpopular and receive press scrutiny, both in the US and the host country, so small, few-hundred person CSL's have the advantage of being able to be set up with, essentially, no publicity. You can think of them as smaller versions of the kind of bases you find in Djibouti or Ascension island which can, rather quickly, become bigger bases should the need arise. The remaining twenty known sites on the continent are what are called contingency locations. Now, this terminology can be used for a lot of different types of facilities, but, in essence, what it means is that these are temporary sites established as part of ongoing missions. For example, the contingency location in Garoua, Cameroon was set up for the Americans to provide logistics and intelligence support in the Cameroonian's fight against Boko Haram. What that actually means, though, when you break through the military's PR language, is that this is a drone base. Unlike other American drone bases, it's relatively easy to find info about the one in Garoua perhaps because it's primarily home to surveillance drones, rather than strike drones. For other contingency locations, though, it is much less clear what exactly their purposes are and for some, they aren't even publicly acknowledged. For many, the US military just has small agreements with foreign governments and the general public gets very little info at all. So, the final, real answer for how many US bases there are abroad is that we don't know. If you define every military installation as a base, compiling all publicly available information, one set of research reached a number of 800. Of course, the real number could be something far different from that but as the general public, there's just no real way to know. But the next question that arises about the US' overseas presence is why? In the era of nuclear weapons that can obliterate any city on earth in an hour, aircraft carriers sailing worldwide with more aircraft than some country's air forces, and airplanes that could land troops in any country on earth in a day, why does the US bother spending so much money maintaining bases in allied countries during peacetime? The primary reason has to do with a military concept known as the loss of strength gradient. This concept essentially theorizes that, the further a conflict is away from a military's home country, the less military power that nation is able to bring to the fight. This is largely because it is, of course, complicated and expensive to bring troops and equipment over long distances. The book that originally defined this loss of strength gradient proposed that the way to counteract this effect was to establish bases outside of a country's home territory since these can help reduce the effective distances to conflict and, therefore, it's easier to bring more power to the fight. The US has certainly taken this concept to heart and has put quite a lot of work into trying to flatten out their loss of strength gradient. That is to say, they want to make it just as likely that the US would win a war in east Asia as North America. As an example of how these bases aid that mission, much of the operations of the US' wars in Afghanistan and Iraq were conducted here—at Ramstein Air Base in Germany. This base and the other surrounding US military facilities in the Rhineland-Palatinate state make up the largest grouping of American service members in the world and one of the largest groupings of Americans anywhere outside the US. The city that Ramstein and many of the other facilities are in is home to only about 100,000 full time residents, however, the American bases are staffed by more than 50,000 personnel at any given time. This makes Ramstein Air Base like a small American city in Europe. It has outposts of plenty of American restaurant chains that you won't find anywhere else in Germany—Johnny Rockets, Chili's, PF Chang's—in addition to an American-style department and grocery store. It has an American post office, an American high school, four baseball diamonds, two American football fields, American suburban style housing, and even campuses of four American universities—University of Maryland, Oklahoma, Central Texas College, and Embry Riddle Aeronautical University. Quite a lot of work is put into making sure that Ramstein is as similar to any base in the US as possible—both in terms of lifestyle and capability. One central role for Ramstein and other US bases in Europe during the wars in Iraq and Afghanistan was as a stopover point for personnel and cargo en route to combat. Ramstein's convenient location, less than a seven hour flight from all of the middle east, where many of the US' recent military operations have been, makes it a pivotal logistics hub since it would be far more complicated to fly personnel and cargo nonstop to theatre over the more than eleven hour flight from the continental US to the Middle East. Still today, with less US presence in the middle east, Ramstein plays a central role in getting US military members to Europe. There are regular flights, typically about twice a week, from Baltimore to Ramstein in addition to a number of regular flights from stateside military bases like Wright-Patterson Air Force Base in Ohio, Dover Air Force Base in Delaware, and McGuire Air Force Base in New Jersey. These are not flights on commercial airlines but rather charter flights available only to members of the military operated by charter companies like Atlas Air and Omni Air International. Beyond its role as a logistics hub, Ramstein's geographic position plays a critical role in the US' use of drones in the Middle East. You see, American drones are communicated with by satellite but, due to the distance between the Middle East and Creech Air Force Base in Nevada, where the communications from the different drone piloting sites across the US are centralized, a single satellite could not convey information from Creech to the Middle East. That's just because there's too much curvature in the earth for a satellite at a reasonable orbit altitude to have line-of-sight with both areas. They could have one satellite relay info to another, but this would significantly increase the time it would take for the signal to travel from Creech to the drone and, when piloting and attacking remotely, one needs as close to real-time communications as possible. Therefore, the signals travel by fiber optic, transatlantic cable from the US to Ramstein where a relay station then sends the signal up to a satellite based over the area that can communicate with America's drones in the Middle East. Without Ramstein, these drones would not be nearly as capable. Beyond convenience and capability, another major reason for America's heavy overseas military presence is power projection. This is a term used by militaries that refers to, according to the US Department of Defense's definition, “the ability of a nation to apply all or some of its elements of national power—political, economic, international, or military—to rapidly and effectively deploy and sustain forces in and from multiple dispersed locations to respond to crises, to contribute to deterrence, and to enhance regional stability.” In this context, it's essentially how fast a country can get to the fight, if a fight should arise. Power projection is as much an offensive power as a defensive one. It's about making sure that every other country in the world knows that America can and potentially will respond to whatever they decide is a threat in a timely manner. According to the US Department of Defense, the four countries that currently present the greatest potential national threat to the US are Iran, Russia, China, and North Korea. Looking at the global map of bases, it's no coincidence that the greatest concentrations of overseas bases are near Russia's population center in the east, in the Middle East, and in East Asia. Meanwhile, there's relatively little US military presence in South America, Africa, South and Southeastern Asia, and Australia since there are fewer threats to the US in these areas. Still, though, the US military has a nearly permanent presence on every continent. Even on Antarctica, where by international treaty militarization is banned, the US military skirts this regulation by dealing with the logistics of supplying American research bases, which is allowed by the treaty. Some might characterize this experience with Antarctic operations as, “convenient,” in the event of any future conflict in this region. While the US' network of overseas bases in only a part of its overall power projection mission, which also includes its nuclear weapons, aircraft carriers, submarines, and more, the main messaging they convey is that the US can get to anywhere fast. But, predictably, these bases are controversial—both at home in the US and abroad. As one example, this is the island of Okinawa, Japan and this is the land used by the US military. On this dense island of 1.5 million, 26,000 US service members man these sites. While the Japanese government is supportive of the US presence in Okinawa and elsewhere in Japan, locally, there have been decades of tensions between Okinawans and the US military. The US bases there have been an economic, social, and environmental burden on the island as, while the US military's presence in Japan as a whole is viewed largely as a benefit for the country, Okinawans are the ones that have to put up with having a large proportion of their home under the control of a foreign military. Okinawans reportedly feel like they're being ignored by mainland Japan and they've therefore been protesting, particularly against a forthcoming base move to a new site on the island, for years. This is the story for pretty much every country that hosts US military bases—they're often considered by foreign governments as a benefit for the country as a whole since it give them an essence of protection by perhaps the most powerful military in the world, but it comes at a burden to the communities the bases are physically located in. In Okinawa, while the bases do provide a decent amount of employment for locals, it's now thought that the island could be better off economically with the land that these bases take up being used for commercial purposes. Back in the US, some believe that their tax dollars are being used to defend other countries. Some consider these overseas bases antiquated in the era of international military alliances like NATO, extensive aviation infrastructure that can get US forces anywhere on earth in a matter of hours, and the deterrent threat of nuclear weapons. Meanwhile, others would argue that they are crucial assets to US diplomacy and power projection. They would argue that their very existence maintains the US' superpower status. This is all to say, simply, that the US military's worldwide presence is controversial… but likely effective. They certainly do make the US military seem more formidable in the international eye which many Americans would consider a positive, but the final, grand question is at what cost? With the cost in dollars, the cost in geopolitical tensions, the cost in community detriment, the simple cost in how the world views the United States as a country, is it worth it? If you're a viewer of Wendover Productions you probably are someone who likes learning about interesting things. One topic that I personally think is quite interesting that I haven't touched much before on this channel is probability. The field of probability is one that seems simple at first but becomes more and more complex with the more you learn and can have some quite useful real-world applications. If you want to learn how to apply the principles of probability, Brilliant has five fantastic courses taking you all the way through the basic to advanced concepts in probability. 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