With increasing knowledge of al-Qaeda, we see that "the presence of American military forces for combat operations on the homeland territory of the suicide terrorists is stronger than Islamic fundamentalism in predicting whether individuals from that country will become al-Qaeda suicide terrorists" (103). "Al-Qaeda is less a transnational network of like-minded ideologues ... than a cross-national military alliance of national liberation movements working together against what they see as a common imperial threat" (104). The nature of Salafism, a Sunni form of Islamic fundamentalism, is complex (105–07). Statistical analysis fails to corroborate Salafism-terrorism connection, but it does corroborate a connection to U.S. military policies in the Persian Gulf (107–17). Al-Qaeda propaganda emphasizes the "Crusader" theme, which is inherently related to occupation (117–24). Pape concludes that "the core features of al-Qaeda" are captured by his theory (125).