The constitutional law expert Louis Henkin summarized the judiciary's role in foreign affairs nicely when he wrote:
Overall, the contribution of the courts to foreign policy and their impact on foreign relations are significant but not large. The Supreme Court in particular intervenes only infrequently and its foreign affairs cases are few and haphazard. The Court does not build and refine steadily case by case, it develops no expertise or experts; the Justices have no matured or clear philosophies; the precedents are flimsy and often reflect the spirit of another day. But though the courts have only a supporting part, it is indispensable and inevitable, and if their competence and equipment for making foreign policy are uncertain, they can be improved by stronger, continuing guidance by Congress and, perhaps, by the President.
In examining the power and practice of the judiciary in foreign affairs, one is struck by the potential power of this branch but the rare use of it in practice. In general, the judiciary has tended to regard foreign affairs as fundamentally different from other areas of power. In so doing, it has been more willing (either through actual rulings or the dismissal of cases as political questions) to permit the federal power under consideration, and to give the president the benefit of the doubt in disputes over executive and legislative branch authority. The blurring of the domestic and international, the increasing activism of state and local governments in foreign affairs, and the form and timing of U.S. military intervention abroad will be major factors in coming years that will determine whether the judiciary's restraint in foreign affairs continues.