d all Treaties made, or which shall be
made, under the Authority of the United States, shall be the supreme Law
of the Land."12
Federal courts have jurisdiction to enforce treaty obligations.
Article III states:
"The Judicial Power shall extend to all Cases, in Law and Equity,
arising under this Constitution, the Laws of the United States, and
Treaties made, or which shall be made, under their Authority;
There is one important exception to the enforcement of treaties in
federal courts. Some treaties, including many human rights treaties, are
considered "non-self-executing." A non-self-executing treaty is one not
intended to become effective as domestic law without the enactment of
further enabling legislation.14 It can be
difficult, however, to determine which treaties are self-executing and
which are not. The Restatement (Third) of Foreign Relations Law declares
an international agreement of the U.S. non-self-executing if: 1) the
agreement makes clear that domestic implementing legislation is needed;
2) the Senate (when consenting to the treaty) requires implementing
legislation; or 3) the Constitution requires implementing
Examples of non-self-executing treaties include any treaties that
require budget outlays.16 Constitutionally,
Congress must authorize budget expenditures. Expenditures cannot
automatically be authorized by ratification of a treaty. Similarly, any
treaty committing the U.S. to declare war under certain conditions is
non-self-executing. Why? A treaty can't require the U.S. to
automatically be at war. Constitutionally, Congress must declare
The U.S. tends to be a cautious treaty signer. It generally takes
very seriously its international obligations under treaties and is
extremely careful before undertaking such obligations. This is
especially true in the area of international human rights. The U.S.
practice has been to ratify relatively few human rights treaties. For
example, the U.S. and Somalia are the only United Nations-member
countries not to have ratified the Convention on the Rights of the
Child.18 In addition, when ratifying, the
U.S. frequently includes many reservations and usually declares the
treaty to be non-self-executing.19
The second major source of international legal norms is customary
law. Under customary law, a nation is bound by certain legal norms even
if it has never signed a treaty containing those norms.
Basic Principles Regarding Custom. A custom is
formed by the "general and consistent practice of states followed by
them from a sense of legal obligation."20
For example, although there is no treaty on point, all nations are bound
by the following custom (a binding principle of international law): a
state may not enforce its domestic law within the boundaries of another
state without that state's consent.21 In
creating a custom, it is not enough for nations to consistently act in a
certain way. They must act that way from a sense of legal obligation (as
opposed, for example, to mere habit or courtesy).
The International Court of Justice considers the following factors in
determining whether there has been a general and consistent practice:
uniformity, consistency, and longevity.22
The first two factors are the most important. At times, a custom can be
formed quite quickly. For example, a 15-year period was deemed
sufficiently long for nations to adopt a custom of using a continental
shelf theory for claims to offshore oil and gas deposits.23 Other examples of legally binding customary
norms are that treaty obligations must be observed by ratifying
nations;24 a state may not detain an
individual indefinitely without charge or trial;25 and a state may not sanction human
A principle does not exist as a matter of customary law if there is
no agreement among states as to the scope and content of that
principle.27 For example, while the
Universal Declaration of Human Rights declares as a fundamental human
right the right to own and to not be arbitrarily deprived of property,
there is widespread disagreement about the exact contours of that right.
Protection of property rights is ther