Legitimate use of military force against state-sponsored - Air University

elevance is international law? Why should we care about it? In addition to the stated US policy
to comply with international law, other important reasons exist as to why international law is
applicable to the conduct of military operations by the United States.
First, as stated by Justice Horace Gray in Paquette Habana, “international law is part of
our law.” 40 The US Constitution, article I, section 8, clause 10 and article III, section 2,
recognizes that the United States is subject to international law and Congress has the power to
define offenses under the law of nations. From the very beginning of our federal republic, US
courts have treated customary international law as an integral part of the law of the United
States. As Prof Louis Henkin, Columbia ‘University, states, “international law is not merely law
binding on the United States internationally but it is also incorporated into United States law.” 41
Violation of international law becomes a breach of US law that can have a significant impact on
us as a nation and as individuals.
International treaty law is also US law, but it is treated somewhat differently. The
Constitution, article VI, clause 2, provides that “all treaties made, or which shall be made, under
the Authority of the United States” are, like federal laws, the supreme law of the land.
Consequently, all laws and treaties of the United States are supreme over state laws, but of equal
status to one another. Thus, a US law passed after a treaty takes effect may prevail over that
treaty without violating the Constitution. Moreover, since the president has the constitutional
capacity to unilaterally denounce a treaty, such action could not be challenged in US courts. In
these circumstances, US law would not be violated even though international law would be, and
the United States could be held accountable by the international community for such action. The
important point to recognize is that customary international law, unlike treaty law, is inherently
part of US law and always applies. Customary law provides the great body of international legal
norms relative to the use of military force. Even those principles concerning the use of force as
are contained in the United Nations Charter, articles 2(4) and 51, are now generally considered
by legal scholars as having become customary international law. Moreover, no matter what the
status of treaty obligations of the United States may be under our law, such obligations bind the
United States internationally until properly terminated in accordance with the law of nations.
Second, democratic societies are established on the rule of law, and compliance with
international law is fundamental to American tradition. In the eloquent words of Abram Chayes,
former State Department legal adviser,
A nation which professes to live by the rule of law invites a sure penalty,
sometimes more swiftly than by the judgment of a court, if it turns from the path
of the law. For us and our associates, moreover, whether we will profess to live by
the law is not an issue of policy on which we have alternatives. The answer is
inherent in our national tradition, in our culture, and it is implied in the purposes
for which we strive in the world. It is implicit in our avowal at birth of “a decent
respect for the opinions of mankind.” Thus it seems to me we will have a hard
time in developing a doctrine as to the use of force which will permit us to be
judge in our own case. 42