With the launch of a new U.S.-led war in Iraq and Syria against the Islamic State (IS), the United States has engaged in aggressive military action in at least 13 countries in the Greater Middle East since 1980. In that time, every American president has invaded, occupied, bombed, or gone to war in at least one country in the region. The total number of invasions, occupations, bombing operations, drone assassination campaigns, and cruise missile attacks easily runs into the dozens.
As in prior military operations in the Greater Middle East, U.S. forces fighting IS have been aided by access to and the use of an unprecedented collection of military bases. They occupy a region sitting atop the world's largest concentration of oil and natural gas reserves and has long been considered the most geopolitically important place on the planet. Indeed, since 1980, the U.S. military has gradually garrisoned the Greater Middle East in a fashion only rivaled by the Cold War garrisoning of Western Europe or, in terms of concentration, by the bases built to wage past wars in Korea and Vietnam.
In the Persian Gulf alone, the U.S. has major bases in every country save Iran. There is an increasingly important, increasingly large base in Djibouti, just miles across the Red Sea from the Arabian Peninsula. There are bases in Pakistan on one end of the region and in the Balkans on the other, as well as on the strategically located Indian Ocean islands of Diego Garcia and the Seychelles. In Afghanistan and Iraq, there were once as many as 800 and 505 bases, respectively.