This chapter considers a phenomenon that has consistently been among the most contentious of modern legal controversies—the application by American courts of international human rights. Recent years have witnessed high-profile conflicts over international human rights law. One major battle involves whether, when, and how U.S. courts should recognize rights set out in the nation's treaty obligations. Another heated area of contention has arisen under an act of Congress, the Alien Tort Statute. Perhaps most heated of all have been debates over the use of foreign legal materials, including customary international law, to interpret the Constitution of the United States. In these areas as well, the Supreme Court, and the judiciary generally, has wavered. Yet once more, a fresh appreciation of the principles the Founders entrenched, the subsequent custom that on balance confirms that original vision, and the consequences of the way nations interact in a globalized age—all these imperatives point away from the path that the judiciary appears more and more to be considering, and back to the course first established.