Short Passages From Key Documents

Compiled by Allen Ferguson, JD, MFA


When the United States is considering armed intervention abroad, an important question is whether the intervention would be legal under international law. This is important, among other reasons, because other nations judge the U.S. partly on the basis of its adherence or non-adherence to norms of international law

This presentation is designed to give you an important tool for evaluating the legality under international law of a proposed use of force: the actual language of key provisions of important international law documents dealing with the legality of illegality of going to war.  To place these provisions in context, we begin with two observations about the relevant characteristics of war.

Certain Characteristics of War

“War necessarily is a calculated series of killings, of destructions of property, of oppressions. Such acts unquestionably would be criminal except that International Law throws a mantle of protection around acts which otherwise would be crimes, when committed in pursuit of legitimate warfare.”

— U.S. Supreme Court Justice Robert Jackson, chief prosecutor for the United States at Nuremberg, Report to President Truman, 1945.

War is a grave affair of state;
It is a place
Of life and death,
A road
To survival and extinction,
A matter
To be pondered carefully.

— Sun Tzu (Chinese strategist, 5th – 4th Century B.C.), The Art of War

Ultimate Goals of International Law Concerning  Use of Force

“We, the Peoples of the United Nations [are] determined to save succeeding generations from the scourge of war, which twice in our lifetime has brought untold sorrow to mankind.”

— UN Charter, Preamble, opening words.

“The purposes of the United Nations are: 1. to maintain international peace and security . . .”

— UN Charter, Chapter I, Article 1

The signatory nations “solemnly declare . . . that they condemn recourse to war for the solution of international controversies, and renounce it as an instrument of national policy  . . .”  They “agree that the settlement . . . of all disputes . . . of whatever nature or of whatever origin they may be, which may arise among them, shall never be sought except by pacific means.”

— Kellogg-Briand Pact, 1928

“Each of the Parties to the Treaty undertakes to pursue negotiations in good faith on effective measures relating to . . . nuclear disarmament, and on a treaty on general and complete disarmament under strict and effective international control.”

— Nuclear Non-Proliferation Treaty, Article 6 (1970)

“Mankind must put an end to war — or war will put an end to mankind.”

— John F. Kennedy to UN General Assembly, 1961.

Basic Rules of International Law Concerning Use of Force

“All Members shall refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any state . . .”

— UN Charter, Ch. I, Art. 2(4)

“All Members shall settle their international disputes by peaceful means in such a manner that international peace and security, and justice, are not endangered.”

— UN Charter, Ch. I, Art. 2(3)

“The parties to any dispute, the continuance of which is likely to endanger the maintenance of international peace and security, shall, first of all, seek a solution by negotiation, enquiry, mediation, conciliation, arbitration, judicial settlement, resort to regional agencies or arrangements, or other peaceful means . . .”

— UN Charter, Ch. VI, Art. 33

“Should the parties to a dispute of the nature referred to in Article 33 fail to settle it by the means indicated in that Article, they shall refer it to the Security Council.”

— UN Charter, Ch. VI, Art. 37

The “planning, preparation, initiation or waging of a war of aggression or a war in violation of international treaties, agreements or assurances . . .” is a “Crime Against Peace.”

— London Agreement establishing Nuremberg Tribunal

“To initiate a war of aggression . . . is not only an international crime, it is the supreme international crime, differing only from other war crimes in that it contains within itself the accumulated evil of the whole.”

— Final Judgment of the Nuremberg Tribunal

Illegal aggression occurs when a state is the first to: (1) declare war; (2) invade the territory of another state with armed force; (3) attack the territory, vessels or aircraft of another state with armed force; or (4) provide support to armed bands in the territory of another state.

— Justice Robert Jackson at Nuremberg, Opening Statement

“The doctrine taught by Grotius, the father of International Law, [holds] that there is a distinction between the just and the unjust war–the war of defense and the war of aggression. . . . It is high time that we act on the juridical principle that aggressive war-making is illegal and criminal.”

— Justice Robert Jackson, chief American prosecutor at Nuremberg, Report to President Truman, 1945

Self-defense Exception to Non-Use of Force

“Nothing in the present Charter shall impair the inherent right of individual or collective self-defense if an armed attack occurs against a Member . . . until the Security Council has taken measures necessary to maintain international peace and security.”

— UN Charter, Article 51

“The requirement of international law that measures taken avowedly in self-defense must have been necessary for that purpose is strict and objective, leaving no room for any measure of discretion.”

— International Court of Justice (“World Court”), Iran Oil Platforms Case (2003)

Security Council Action Exception to Non-Use of Force

“Should the Security Council consider that measures [not involving the use of armed force] would be inadequate or have proved to be inadequate, it may take such action by air, sea, or land forces as may be necessary to maintain or restore international peace and security.”

— UN Charter, Chapter VII, Article 42

Legality of Preemptive Strikes

“Preventive action in foreign territory is justified only in case of  ‘an instant and overwhelming necessity for self-defense, leaving no choice of means, and no moment of deliberation.'”

— Final Judgment at Nuremberg (1947), quoting  Secretary of State Daniel Webster in the Caroline Case

Sovereign Equality of States

“We the Peoples of the United Nations [are] determined to reaffirm faith in . . . the equal rights of . . . nations large and small.”

— UN Charter, Preamble

“The [United Nations] Organization is based on the principle of the sovereign equality of all its Members.

— UN Charter, Ch. I, Art. 2(1)