The friend of my enemy is my enemy: International alliances and international terrorism

Terrorism is an instrument for groups that cannot achieve their political goals legally. One important strategic function of terrorism is to weaken the government – either directly by attacking representatives or supporters of the government or indirectly by causing a political response that is unpopular among the population. Often, however, political stability of the home government is buttressed by foreign powers. In this case, the terrorists can have a strategic interest in attacking nationals of these foreign countries. This article analyses this logic by looking at international alliances as a proxy for international support. If the friend of my enemy is my enemy, then terror entrepreneurs, which seek to overthrow their home country's government (the enemy), may find it attractive to target nationals of the foreign allies of their country (the friends of the enemy). The theory in this article predicts that attacking nationals of a foreign ally is particularly attractive if this ally is militarily more powerful than the home country. Moreover, the combined effect of alliance and relative power differentials becomes stronger the more democratic the ally and becomes weaker the more democratic the terrorists' home country. Empirical support for the hypotheses in this article is found in an analysis of a directed country dyad sample of international terrorism.