Afghanistan has been the center of competing foreign powers for more than a century. Between 1839 and 1919, the British fought three wars in Afghanistan, each lasting no more than a few months or years (although the last war was more like a skirmish). During the first two wars, the British Empire wanted to secure the country against Russia’s influence, says Shah Mahmoud Hanifi, a professor of Middle Eastern and South Asian history at James Madison University. During the third, it wanted to secure Afghanistan against the Ottoman Empire.

Similarly, the Soviet Union’s occupation of the region between 1979 and 1988 was bound up in its competition with the United States during the Cold War. The CIA covertly armed Afghanistan’s mujahideen (or “strugglers”) during that war, meaning that the Soviets were fighting a country greatly helped by another empire.

The United States entered Afghanistan in October 2001 as part of its War on Terror following the attacks of 9/11. The goal was to defeat Al-Qaeda and the Taliban quickly and decisively. But the conflict then dragged on for nearly 20 years.

Afghanistan’s strategic location—it connects Central Asia and the Middle East to South and East Asia—makes it a “kind of a policy way station towards a political agenda,” explains Hanifi. So when large empires go to war in Afghanistan, they come up against other countries’ attempts to exert their own influence in the region. The same is true today. Just as the U.S. secretly armed the mujahideen, NATO has accused Iran of arming the Taliban in Afghanistan.

There are many other factors that make Afghanistan a tough place to wage war in. Logistically, the terrain makes it difficult to move people and equipment. In addition, “the geographic factors of terrain inform cultural values,” says Hanifi, meaning that outside forces don’t always understand the unique relationship between the country’s 14 recognized ethnic groups and its various tribes.

During its military engagement in Afghanistan, U.S. forces emphasized working with Pashtuns in creating a government in Afghanistan. But although they’re the ethnic majority, Pashtuns are spread across multiethnic and multilingual tribes.

In the summer of 2021, the United States began withdrawing its remaining troops from the region. After a nearly 20-year-long U.S. combat mission in Afghanistan, Taliban forces quickly retook control of the nation's key cities.