In his influential 1939 treatise against utopian thinking in foreign policy, The Twenty Years’ Crisis, E.H. Carr made an analogy with domestic politics that seemed so obvious at the time it needed neither elaboration nor justification. “It is not the ordinarily accepted moral duty of a state to lower the standard of living of its citizens by throwing open its frontiers to an unlimited number of foreign refugees,” he wrote, “though it may be its duty to admit as large a number as is compatible with the interests of its own people.” That the same principle might apply to economic migrants was presumably too self-evident to merit stating.
