In the last 15 years, terrorist organizations based in the Middle East have recruited Muslims in the United States and Europe via social media. The number of European and American Muslims joining terror organizations has dramatically grown. However, little is known about the factors that drive Muslims in Western countries to become radicalized. Current research suggests that cultural identities and attitudes towards extremism contribute to radicalization. For example, evidence suggests immigrants who identify with neither their heritage culture nor the culture of their host country feel doubly marginalized, insignificant, and are more likely to radicalize. Similarly, social isolation and discrimination against Muslims living in Western countries may also contribute to radicalism. Therefore, it is imperative that policymakers engage in efforts to address the social isolation and marginalization of Muslim Europeans and Americans.