“…Failing to account for these interests leads to bias in the estimation of the impact of alliances on conflict (Levy, 1981;Bearce, Flanagan and Floros, 2006). In the same vein, poor economic conditions are thought to increase the risk of terrorism (Blomberg, Hess and Weerapana, 2004;Freytag, Krüger, Meierrieks and Schneider, 2011;Meierrieks and Gries, 2012), but important variables such as political freedom affect both the state of the economy and the incidence of terrorism (Grier and Tullock, 1989;Krieger and Meierrieks, 2011). Even weather, often used as an instrumental variable because of its independence from human influence, has become endogenous to anthropogenic climate change in studies of civil conflict (see, e.g., Tir andStinnett 2012 andTheisen 2012).…”