The words "foreign affairs" are not to be found in the United States Constitution. There are scattered references to "commerce with foreign nations," to TREATIES and ambassadors, to the law of nations, but there is nothing to suggest that the relations of the United States with other nations form a significantly discrete constitutional category. Yet every major theme of constitutional jurisprudence is played differently in respect of foreign affairs. Foreign affairs provide a unique exception to the dogma that the federal government has only the powers expressly enumerated in the Constitution. For the relations of the United States with other countries, FEDERALISM is virtually irrelevant and the United States is essentially a unitary state. The separation and allocation of authority among the branches of the federal government for conducting foreign affairs are different from what they are in respect to domestic matters. Individual rights, strongly safeguarded by the Constitution in the internal life of the country, bow quite readily before the foreign interests of the United States. In this and in other respects foreign affairs discourage JUDICIAL REVIEW and intervention, the hallmark of United States constitutionalism.
The Constitution vests some foreign affairs powers in the federal government in the same manner in which it vests domestic powers, by bestowing them on one or another of the three branches of that government. Thus, Congress in Article I, section 8, is given the power to regulate commerce with foreign nations, to define offenses against the law of nations, and to declare war. The President has the power under Article II, section 2, to appoint ambassadors and make treaties (with the ADVICE AND CONSENT of the Senate). The JUDICIAL POWER of the United States extends, according to Article III, section 2, to cases arising under treaties, and to certain controversies involving foreign states, their public ministers, or their citizens. Many powers of government relating to foreign affairs, however, are not mentioned: for example, the power to control IMMIGRATION, to regulate ALIENS in the United States or United States nationals abroad, to assert the rights of the United States and to respond to claims by other governments, to participate in the international process of developing customary law, to make international agreements other than treaties, to recognize states and governments, or generally to determine national policy and attitudes on friendship and intercourse with other nations. While some missing powers can plausibly be inferred from ENUMERATED POWERS, others cannot, and, under general principles, powers not enumerated and not fairly to be inferred from expressed powers were not granted to the federal government: the legislative powers of Congress are limited to those "herein granted" (Article I, section 1), and the powers not delegated to the United States are reserved to the states or to the people by the TENTH AMENDMENT. Yet the federal government has exercised all these foreign affairs powers and others from the beginning, and no one has doubted that the federal government had that authority, and that the states did not.
In foreign affairs, then, the principle that the federal government has only the enumerated powers does not apply. All foreign affairs are delegated to the federal government as though that were expressly provided. A hundred years ago the Supreme Court, in CHAE CHAN PING V. UNITED STATES (1889), held, for example, that Congress has the power to regulate immigration because the power to exclude or admit aliens is inherent in the nationhood and SOVEREIGNTY of the United States. In UNITED STATES V. CURTISS-WRIGHT EXPORT CORP. (1936) the Supreme Court expounded a special constitutional principle:
The broad statement that the federal government can exercise no powers except those specifically enumerated in the Constitution, and such implied powers as are NECESSARY AND PROPER to carry into effect the enumerated powers, is categorically true only in respect of our internal affairs. In that field, the primary purpose of the Constitution was to carve from the general mass of legislative powers then possessed by the states such portions as it was
thought desirable to vest in the federal government, leaving those not included in the enumeration still in the states.? And since the states severally never possessed international powers, such powers could not have been carved from the mass of state powers but obviously were transmitted to the United States from some other source.?
As a result of the separation from Great Britain by the Colonies acting as a unit, the powers of external sovereignty passed from the Crown not to the colonies severally, but to the colonies in their collective and corporate capacity as the United States of America.?
The Union existed before the Constitution, which was ordained and established among other things to form "a more perfect Union." Prior to that event, it is clear that the Union, declared by the ARTICLES OF CONFEDERATION to be "perpetual,' was the sole possessor of external sovereignty and in the Union it remained without change save in so far as the Constitution in express terms qualified its exercise. The Framers' Convention was called and exerted its powers upon the irrefutable postulate that though the states were several their people in respect of foreign affairs were one.?
It results that the investment of the federal government with the powers of external sovereignty did not depend upon the affirmative grants of the Constitution. The powers to declare and wage war, to conclude peace, to make treaties, to maintain diplomatic relations with other sovereignties, if they had never been mentioned in the Constitution, would have vested in the federal government as necessary concomitants of nationality.?As a member of the family of nations, the right and power of the United States in that field are equal to the right and power of the other members of the international family. Otherwise, the United States is not completely sovereign. The power to acquire territory by discovery and occupation ? the power to expel undesirable aliens ? the power to make such international agreements as do not constitute treaties in the constitutional sense ?, none of which is expressly affirmed by the Constitution, nevertheless exist as inherently inseparable from the conception of nationality. This the court recognized, and ? found the warrant for its conclusions not in the provisions of the Constitution, but in the law of nations.
Although the theory underlying Curtiss-Wright has been criticized, it has never been questioned by the Supreme Court. In any event, the DOCTRINE resulting from the theory?plenary power of the federal government in matters relating to foreign affairs, beyond those explicitly granted in the Constitution?is firmly established. The Supreme Court has not often found it necessary to resort to "sovereignty" or "nationhood" as a source of power for the federal government. In large part, the foreign activities of the federal government that have come to court are amply supported by enumerated powers of Congress or the President, by powers reasonably implied in enumerated powers, or by construction of the Constitution as a whole. But sovereignty, nationhood, and their implications in international law and in the practice of other nations are ever available as a source of authority to supply any lack of enumerated power for the federal government in matters relating to foreign affairs. The network of regulation of immigration and of aliens in the United States, for a principal example, rests ultimately on United States sovereignty, and other exercises of authority not easily rooted in enumerated powers have been supported as exercises of "the foreign affairs powers" of Congress, with citations to Curtiss-Wright.
The powers expressly conferred upon branches of the federal government, and those additional powers implied in sovereignty, give the federal government full authority to act in the United States and for the United States in respect to its foreign affairs. Since plenary power has been delegated, state authority, STATES ' RIGHTS, even state immunity (except in remote, hypothetical respects) do not limit federal authority in foreign affairs. When the federal government acts, its action is supreme, superseding any inconsistent state law. Federal action may also preempt, "occupy a field," excluding state action even if it is not inconsistent.
Some state actions in foreign affairs are excluded by Article I, section 10, even when the federal government has not acted. A state may not make a treaty. It may enter into an "Agreement or Compact" with a foreign nation only with the consent of Congress. Although here, as for other purposes, the difference between a treaty and another international agreement is uncertain, presumably if Congress should consent to an agreement by a state with a foreign government the agreement would not be successfully challenged as being a treaty to which Congress could not consent. An agreement requiring the consent of Congress may be formal or informal, even tacit. But, by analogy to doctrine that has developed in cases such as Virginia v. Tennessee (1893), with respect to compacts between states of the United States, probably a state may make a compact with a foreign government without congressional consent if the agreement does not tend to "the increase of political power in the states, which may encroach upon or interfere with the just supremacy of the United States."
The states are limited also by implication of the grant to Congress of power "to regulate commerce with foreign Nations and among the several States." Although that doctrine of implied limitations developed principally in respect of INTERSTATE COMMERCE it applies in essentially the same way to...