Abstract
Foreign terrorist fighters (FTFs), broadly understood, are individuals who travel abroad to fight in civil wars and insurgencies. This chapter provides an overview of the FTF phenomenon, followed by a discussion of the difficulties that scholars have in determining just who is an FTF. In contemporary times, FTFs were notable in the Afghan civil war. FTFs played a surprisingly successful role in the Afghan civil war, ultimately pushing the Soviets out of Afghanistan entirely. It is estimated that 20,000 to 25,000 FTFs traveled to Afghanistan between 1984 and 1992. One of the difficulties with determining who is and who is not an FTF is that it is often hard to distinguish FTFs from mercenary soldiers. The rise of the Islamic State resulted in more than 30,000 people traveling to Iraq and Syria to become FTFs. It is estimated that 20% of these volunteers were from Western countries.