Denaturalization is the loss of citizenship against the will of the person concerned. Denaturalization is often applied to ethnic minorities and political dissidents. Denaturalization can be a penalty for actions considered criminal by the state, often only for errors in the naturalization process such as fraud. Since the 9/11 attacks, the denaturalization of people accused of terrorism has increased. Because of the right to nationality, recognized by multiple international treaties, denaturalization is often considered a human rights violation. Definition Denaturalization is the case in which citizenship or nationality is revoked by the state against the wishes of the citizen. In practice, there may not be a clear-cut distinction between non-consensual revocation and renunciation of citizenship. Some sources distinguish denaturalization, as the reversal of naturalization, from denationalization, as the revocation of citizenship more generally. History Denaturalization can be considered a new form of the ancient custom of banishment, which decreased in use after the establishment of prisons and the reduction in territory considered terra nullius. The British practice of penal transportation led to 380,000 people being sent into exile in other parts of the empire through the mid-nineteenth century. The modern practice of denaturalization developed in the late nineteenth century at the same time as immigration controls. Following the growth of the welfare state, emigration and denaturalization were legalized by many countries for pragmatic reasons in order to avoid having to support poor returnees. The German Empire denaturalized all emigrants who had been abroad for ten years to avoid the return of unsuccessful emigrants. Naturalized citizens who returned to their country of origin also faced loss of their new nationality as they were considered to have cut their ties with that country. In Canadian nationality law, this practice continued until 1974. French law allowed for denaturalization since the late nineteenth century but was rarely used before World War I. According to the modern state system, states have a duty to admit their own nationals and may expel non-nationals. Throughout much of the Western world, denaturalization laws were passed in the early twentieth century, including the Naturalization Act of 1906 in the United States, French laws in 1915 and 1927, and the British Nationality and Status of Aliens Act in 1914 and 1918. World War I enhanced scrutiny of the loyalty of naturalized citizens, leading to an increase in denaturalization; nearly all belligerents used denaturalization. In many cases, political dissidence (especially Communist