Treaties are legally binding and obligate Congress to implement legislation.
Henkin ’96 [Louis; November; Professor Emeritus at Columbia Law School, former president of the American Society of International Law, LL.B from Harvard University; Foreign Affairs and the United States Constitution, “Treaties, the Treaty Power, and Executive Agreements,” Ch. 7]
The difference between self executing and non self executing treaties is commonly misunderstood. Whether a treaty is self executing or not, it is legally binding on the United States. Whether it is self executing or not, it is supreme law of the land. If it is not self executing, Marshall said, it is not `a rule for the Court'; he did not suggest that it is not law for the President or for Congress. It is their obligation to see to it that it is faithfully implemented; it is their obligation to do what is necessary to make it a rule for the courts if the treaty requires that it be a rule for the courts, or if making it a rule for the courts is a necessary or a proper means for the United States to carry out its obligation.*