Two variables hypothesized to be relevant to the radicalisation of immigrants are examined. The first one is the degree to which the host society makes them feel welcome and helps them fill a role in society-at-large, which facilitates their integration. A comparison is offered between European societies on the one hand, and long-standing immigration countries such as the US, Australia, and Canada on the other hand. It is argued that a significant ingredient is that the latter do not define themselves as nation-states, and, on the whole, define belonging to the nation as independent of descent. The second variable is the fit between the culture of origin of the immigrant and that of the host country. It has been shown that adjustment is a function of that fit. In individualistic countries, people with an allocentric orientation tend to be poorly adjusted, whereas the reverse is true in collectivist countries, where the ones with an idiocentric orientation are at a disadvantage. This has implications for people from an Islamic background coming to a nation with a Western culture.