In fact, as a result of the proliferation of executive agreements in 1972, Congress, relying on the “necessary and proper” clause, passed the Case-Zablocki Act,15 which requires regular reporting to the Senate about ongoing international negotiations.16 It provides Congress with surveillance power over executive agreements as the secretary of state must send to Congress the text of any international agreement to which the United States is a party, including oral ones, other than a treaty (by constitutional standards), within sixty days of the agreement coming into force. Moreover, the president under his or her own signature, “not later than March 1, 1979, and at yearly intervals thereafter,” must transmit to Congress a report concerning what agreements were negotiated after the expiration of the sixty-day period with an explanation for the delay.17
Early executive agreements were mostly made pursuant to legislation or joint resolution of Congress. The executive agreement pursuant to legislation avoids having to obtain the advice and consent of a supermajority of the Senate. Today, executive officials cite the early cases to conclude that such historical reality legitimizes the use of executive agreements.
In the original draft of the Constitution, the Committee of Detail assigned the treaty power solely and exclusively to the Senate. The shift to a shared executive-Senate function requiring a supermajority vote in the Senate reveals a desire for a higher degree of consensus for passage of an international agreement than for ordinary law. In fact, a proposal at the Constitutional Convention that international law be made by the president and a simple majority of both chambers of Congress was rejected. In light of this history, it is interesting that the executive agreement plus joint resolution is one of the accepted treaty alternatives.
Significant events in U.S. history have occurred pursuant to these other agreements. For example, the annexation of Texas in 1845 was accomplished by executive agreement plus joint resolution. The President opted for that alternative after the Senate vote did not yield the two-thirds supermajority necessary for a constitutionally defined treaty.18 More recently, and significant to this volume, a constitutional challenge to the validity of the North American Free Trade Agreement (NAFTA), based on its being concluded as a congressional-executive agreement, failed.19
Clear constitutional language on treaties notwithstanding, presidents have come to treat the formal agreements together with sole executive agreements and executive agreements plus joint resolution as interchangeable. Even the U.S. Department of State endorses these three alternative approaches to making international agreements: (1) agreements pursuant to treaty; (2) agreements pursuant to legislation; and (3) agreements pursuant to constitutional authority of the president: (a) as chief executive representing the nation in foreign affairs, (b) to receive ambassadors and other public ministers, (c) as commander in chief, and (d) to take care that the laws be faithfully executed.20
These trends notwithstanding, there are some subjects that warrant an agreement that follows the traditional constitutional Article II treaty process.21 These include themes that are central to this volume: human rights, boundaries, immigration, intellectual property, taxation, the environment, and agreements to join international organizations (most but not all). On the other hand, it is advantageous to have the flexibility of utilizing different forms of international agreements as other matters key to this work are within the traditional congressional-executive realm: trade and finance, for example.
Because the U.S. Constitution gives authority in Article I, § 8, to both houses of Congress to conduct foreign commerce (another term for international trade), and to the executive branch in Article II, § 1, “to make treaties,” the responsibility to negotiate trade agreements is shared and is treated specially under U.S. law. Through periodically renewed “fast-track authority” legislation, the Congress sets forth detailed U.S. trade negotiating objectives to be followed by the executive in reaching agreement on, for example, establishment or revision of World Trade Organization (WTO) Agreements or regional agreements such as the NAFTA or the U.S.-Chile Free Trade Agreement (FTA).22
After consulting with congressional trade committees, the executive signs the trade agreement with his counterparts, then the president formally notifies the text of the agreement to both houses of Congress for the drafting of implementing legislation that will exercise whatever discretion is given the signatories by the agreement’s terms. Congress may not make revisions to the agreement at this stage, else the negotiating credibility of the United States would be destroyed. The agreement and legislation must be considered quickly (thus the legislation’s nickname) and, if both houses of Congress agree, the implementing legislation will also “approve” the agreement—the final step in making it binding on the United States as a “treaty” within the meaning of the Vienna Convention, if not within the meaning of the U.S. Constitution.
Several observations regarding custom, treaties, their relationship to each other, their role as U.S. law, and some principles of U.S. law are appropriate. Article VI of the Constitution makes treaties the law of the land. Therefore, an Article II treaty has the status of domestic law in addition to being international law. Courts of the United States must give effect to international law and to international agreements. A non-self-executing agreement, however, will not be given domestic effect absent implementing legislation. An agreement is non-self-executing if by its terms the agreement evinces an intent that it is not to become domestic law absent implementing legislation or if the Senate, in giving its advice and consent, or Congress in a joint resolution, expressly notes that the treaty requires implementing legislation to become effective as domestic law. In addition, there may be instances in which implementing legislation may be constitutionally required. An international agreement cannot take effect as domestic law without implementation by Congress if the agreement would achieve what lies within the exclusive law-making power of Congress under the Constitution. For example, an international agreement creating an international crime could not become part of U.S. criminal law without the appropriate congressional enactment.23
As noted above, both custom and treaties are part of U.S. law as well as of international law. Custom and treaties, both primary sources of international law, are of equal authority in the international realm. Absent the expression of intention to the contrary, the later in time rule applies to resolving conflicts between custom and treaty: a rule established by treaty will displace a prior inconsistent customary norm, except if the prior custom is a peremptory norm from which no agreement can derogate. Conversely, if there is a clear intent, a later customary norm will supersede a prior inconsistent conventional obligation.24
Similarly, there is a later in time rule that applies in instances of inconsistency between a U.S. domestic norm and an international norm—be it customary or conventional. Under the Constitution, treaties and statutes are coequal, much like treaties and custom are coequal. Article VI of the Constitution, the Supremacy Clause, creates this relationship. Specifically, the article provides that “this Constitution, and the laws of the United States which shall be made in pursuance thereof; and all treaties made, or which shall be made, under the authority of the United States, shall be the supreme law of the land.”
Thus, given their coequal status, if congressional intent is clear, a later congressional act supersedes an earlier international norm. In this regard, two observations are appropriate. One, unless there is a clear intent to the contrary, domestic rules will be interpreted as far as possible to be consonant with existing binding international norms. Consequently, the later in time rule will be applied so as not to conflict with international law. Two, even if the clear congressional intent exists to supersede the international norm, while as a matter of domestic law the new domestic norm is binding in U.S. domestic courts, the rule of international law that is superseded domestically is still binding on the state internationally and the state remains internationally obligated to obey the norm.
The later in time rule also operates when a treaty is adopted that has a provision that conflicts with existing domestic law or treaty so that the later in time prevails. In effect, a later treaty—and in the United States this includes all its functional equivalents, such as the sole executive agreement and the executive agreement plus joint resolution—can supersede domestic law so long as the subject matter lies within the constitutional authority of the body or bodies