Treaties shouldn’t trump U.S. law

JULIAN KU is an associate professor of law at Hofstra University School of Law in New York. He and nine other law professors filed an amicus brief in support of the respondents in the above cases. He blogs at

POLICE OFFICERS across the country may soon have to add a new question to the list of constitutionally required Miranda rights. In addition to the right to remain silent and the right to an attorney, officers soon may be required to ask every arrestee whether he is a foreign national who wishes to contact his consular officials. If the officers fail to ask this question, any defendant who is a foreign national may then have a right to suppress evidence against him or to seek a new trial.

The sole basis for creating this sweeping new right for millions of criminal defendants is a single provision in the Vienna Convention on Consular Relations, a treaty ratified by the United States in 1969. In two upcoming cases, Sanchez-Llamas vs. Oregon and Bustillo vs. Virginia, the Supreme Court is being asked to adopt a treaty interpretation that has been rejected by every U.S. administration, the lower appellate courts and every foreign court that has interpreted the treaty, as well as the high court’s own prior decisions.

Such an aggressive interpretation would threaten the constitutionally protected right of the states to manage their own criminal justice systems. It also would give anti-internationalists in the Senate a powerful argument against joining new international human rights treaties, rightly claiming that activist judges could adopt radical interpretations far beyond the text or intentions of the treaty makers.

Moises Sanchez-Llamas, who is from Mexico, and Mario Bustillo, from Honduras, were convicted of attempted murder and murder, respectively. Both Sanchez-Llamas and Bustillo admit that they received the full panoply of rights guaranteed by the U.S. Constitution, including their Miranda rights to remain silent and to contact a lawyer. They nonetheless argue that the failure of police to notify them of their consular treaty rights entitles them to a new trial or the suppression of evidence against them.


While a number of leading attorneys, legal scholars and former diplomats have filed briefs in support of Sanchez-Llamas and Bustillo, there are serious flaws in their interpretation of the treaty. First, because treaties typically involve relations between governments, there is a standard presumption against finding an individual right in a treaty unless that right is explicitly spelled out. The Vienna Convention speaks of the rights of consular officers to be notified of the arrest, rather than a right of the foreign national who is being arrested.

Moreover, because most foreign countries do not require their police to notify arrested individuals of their constitutional rights or to suppress illegally obtained evidence, it is inconceivable that the Vienna Convention requires suppression of evidence seized in violation of the treaty.

Against this mountain of domestic and foreign precedent, the petitioners can cite only one legal authority: the International Court of Justice in The Hague. In two recent decisions, that court found that the treaty creates an individual right for foreign nationals and also requires host countries to allow review and reconsideration of treaty violations in cases where foreign nationals have been sentenced to death.

Even if these decisions support the petitioners’ interpretation (which they may not), the Supreme Court has no legal obligation to follow or give deference to International Court of Justice rulings -- especially when the interpretation would threaten U.S. constitutional precedents. For instance, it is well settled that principles of federalism prevent Congress from requiring state courts to suppress evidence obtained in violation of a federal statute. Adopting Sanchez-Llamas’ and Bustillo’s interpretation would allow a treaty to regulate state courts in a way that no federal statute ever could.


Treaties are often unfairly viewed with suspicion because of fears that future courts will expand them far beyond the intentions of those who created the treaty. In many cases, such fears undermine the ability of the U.S. to join treaties that advance important national interests such as the advancement of human rights. The Supreme Court could go a long way toward calming those fears by rejecting this latest invitation to engage in judicial treaty activism.