The core argument of the book runs something like the following. Globalization is a powerful force that is transforming American society. Increased globalization brings many benefits, as well as potential problems, to the U.S. While greater international cooperation will be needed, some aspects of what is called global governance present serious challenges to the American political and legal system. The American polity is built on the principle of popular sovereignty; thus, ultimately, authority and sovereignty reside in the people, not the government. In this sense, American sovereignty differs from traditional Westphalian sovereignty. The people are the principal, and the federal government and state governments are the agents of the people. Popular sovereignty is exercised through the Constitution and particularly through separation of powers and federalism. These devices provide checks and balances on the federal government and limit the authority of both the federal government and state governments. New trends in international law directly challenge American popular sovereignty. The key issue is how to accommodate globalization within the American constitutional system. The task at hand is to ensure that the global rules that we choose to follow are incorporated into American law through our constitutional democratic process. Finally, it is possible to accommodate globalization to popular sovereignty.
To accomplish this goal of obtaining the benefits of globalization while preserving American popular sovereignty, Yoo and Ku propose three “doctrinal devices”: 1) a presumption that treaties are non-self-executing, 2) presidential discretion in interpreting customary international law, and 3) a reasonable degree of state autonomy in areas of law reserved to the states by the Tenth Amendment. These doctrines would ensure that the political (i.e., elected and democratic) branches of government — and not simply federal judges — incorporate or not incorporate (as they see fit) international law into domestic American law.
If most treaties were not self-executing, they would require congressional legislation and presidential signature (in addition to the approval of two-thirds of the Senate) in order to become part of American law. Thus, the House of Representatives, the most “democratic” branch of the federal government, would be involved in incorporating treaty law into American domestic law. This additional democratic step would, as Yoo and Ku point out, strengthen the legitimacy of those international laws that we decide should be part of American law.
Customary international law or non-treaty global law has traditionally been recognized through the longstanding practice of nation-states — for example, nations should not kill other nations’ ambassadors. In recent years, transnationalists have attempted to greatly expand the reach of customary international law to include global “norms” on criminal justice, social concerns, and warfare that the U.S. has explicitly rejected.
To ensure the participation of the more democratic branches of the federal government, Yoo and Ku propose that the policy interpretation of customary international law be primarily in the hands of the executive, which has the constitutional authority (and expertise) in foreign policy. Meanwhile, the incorporation of customary law into American domestic law should follow the normal constitutional process — as legislation approved by both houses of Congress and signed by the president.
Yoo and Ku point out that the Tenth Amendment does not disappear when the U.S. signs a treaty or adopts new customary international law. They cite the Supreme Court’s Medellín decision (2008). In this case, the court gave Texas the green light to execute a convicted murderer who was a Mexican national, despite complaints by the International Court of Justice (backed by the American Bar Association) that the U.S. had violated its commitments under the Vienna Convention on Consular Relations by failing to notify the Mexican consulate. The Court declared the Vienna Convention non-self-executing and, in the absence of federal legislation, state law prevailed. The Court also rejected an appeal by the Bush administration to prevent Texas from carrying out the sentence. Taming Globalization notes that, in ratifying international human-rights treaties, Congress almost always includes “federalist” reservations that insist upon a measure of state autonomy in those areas constitutionally reserved for the states.