Ukraine War, April 1, 2022 (III): All weapons delivered to Ukraine to repel Russian invasion are “defensive” weapons


Due to rapidly-breaking developments and in order to facilitate readers’ access to the latest dispatches, we are publishing this article as it is being written. please check back for updates and additions.

To see a list of previous articles, enter “Ukraine” in the Search Box on the upper right, on The Trenchant Observer web site, and you will see a list in chronological order.


1) Helene Cooper, “U.S. Will Help Transfer Soviet-Made Tanks to Ukraine,” New York Times, April 1, 2022 (8:35 p.m. EDT);


The right of self-defense under the United Nations Charter

International law has been developed over the last 400 years in order to define terms and establish agreed-upon concepts, which are the building blocks of international law norms whose meaning is commonly understood and whose obligatory character is accepted by the overwhelming majority of states.

As norms developed prohibiting resort to war and the illegal use of force, there was always one exception that was universally understood and accepted: the right of self-defense.

In the U.N. Charter of 1945, the prohibition of the threat or use of force contained in Article 2 paragraph 4 is subject to the exception of “the inherent right of individual or collective self defense in the case of an armed attack”, under article 51 of the Charter. The right of self-defense is “inherent”, not granted by the Charter, because it was understood that it had always existed.

In international law, in a manner similar to the domestic law of self-defense in most countries, the right of self defense is subject to two requirements, in addition to the Charter requirement of a prior “armed attack”.

Those are the requirement of necessity, the necessity to halt and repel the attack, and the requirement of proportionality, i.e., that exercise of the right be proportional to the nature and scale of the attack.

While international lawyers can and do argue about the fine details of these requirements in special or hypothetical situations, none of their arguments are relevant here, in the case of the Russian invasion of Ukraine and measures Ukraine can take in exercise of the right of self-defense.

Nonetheless, policymakers, particularly in the U.S., are not adequately schooled in modern international law and how it actually applies in specific situations. Many decision makers in the U.S. and other countries hold such simplistic views of international law that sophisticated experts are not included in the highest decision making circles.

A dramatic illustration of this point is the fact that Secretary of State Anthony Blinken has not filled the position of State Department Legal Adviser, the highest international law position in the government, some 14 months after taking office.

As a result, the basic clarity which international law might provide is often absent from foreign policy devision making. This often results in extremely muddled thinking.

The distinction between “offensive” and “defensive” weapons in U.S. military assistance legislation

Nowhere is this muddled thinking more evident, and of potentially greater consequence, than in the spurious distinction that is made between “offensive” and “defensive” weapons.

The distinction has its origin in U.S. domestic legislation providing for military assistance to certain countries which for one reason or another (usually human rights violations) are subject to bans on the export or sale of weapons.

However, successive administrations have succeeded in getting around such bans by arguing that the weapons involved are “defensive” weapons, and consequently fall within the customary self-defense exception typically contained in such legislation.

This has led to corruption in the thinking about permissible military assistance to a country which is a victim of armed aggression, such as Ukraine.

All weapons supplied to Ukraine to repel the Russian invasion are defensive weapons under article 51 of the U.N. Charter.

Mig 29’s, which might be considered by some as “offensive” weapons because they could be used to strike targets in Russian territory, are legitimate weapons to be used in exercise of the inherent right of self-defense.

There is nothing illegal or inappropriate about Ukaine bombing fuel depots in Russia which are used to support the Russian invasion of Ukraine.

Moreover, it would be wholly appropriate and legal for Ukraine to bomb or target missiles against sites on Russian territory which are launching missiles at Ukrainian cities and civilian populations.

Such actions would, in fact, be purely defensive operations undertaken in exercise of the right of self defense under the Charter and international law.

Similarly, bombing or targeting missiles at launching sites in Belarus from which missiles are being launched against Ukrainian cities would be wholly justified defensive operations under international law.

Likewise, the provision to Ukraine of advanced radar and anti-missile installations to assist in conducting such defensive operations would be fully justified as an exercise of the right of collective self-defense under Article 51 of the U.N. Charter.

As would the transfer Polish Mig 29’s to Ukraine.

NATO and the U.S. need to stop worrying about how Putin might perceive their actions, and start delivering to Ukraine the weapons they need to repel or defeat the invading Russian army.

The Trenchant Observer

About the Author

James Rowles
"The Trenchant Observer" is edited and published by James Rowles (aka "The Observer"), an author and international lawyer who has taught International Law, Human Rights, and Comparative Law at major U.S. universities, including Harvard, Brandeis, the University of Pittsburgh, and the University of Kansas. Dr. Rowles is a former staff attorney at the Inter-American Commission on Human Rights (IACHR) of the Organization of American States OAS), in Wasington, D.C., , where he was in charge of Brazil, Haiti, Mexico and the United States, and also worked on complaints from and reports on other countries including Argentina, Chile, Uruguay, El Salvador, Nicaragua, and Guatemala. As an international development expert, he has worked on Rule of Law, Human Rights, and Judicial Reform in a number of countries in Latin America, the Caribbean, Africa, the Middle East, South Asia, and the Russian Federation. In the private sector, Dr. Rowles has worked as an international attorney for a leading national law firm and major global companies, on joint ventures and other matters in a number of countries in Europe (including Russia and the Ukraine), throughout Latin America and the Caribbean, and in Australia, Indonesia, Vietnam, China and Japan. The Trenchant Observer blog provides an unfiltered international perspective for news and opinion on current events, in their historical context, drawing on a daily review of leading German, French, Spanish and English newspapers as well as the New York Times, the Wall Street Journal, the Washington Post, and other American newspapers, and on sources in other countries relevant to issues being analyzed. Dr. Rowles speaks fluent English, French, German, Portuguese and Spanish, and also knows other languages. He holds an S.J.D. or Doctor of Juridical Science in International Law from Harvard University, and a Doctor of Law (J.D.) and a Master of the Science of Law (J.S.M.=LL.M.), from Stanford University. As an undergraduate, he received a Bachelor of Arts degree, also from Stanford, where he graduated “With Great Distinction” (summa cum laude) and received the James Birdsall Weter Prize for the best Senior Honors Thesis in History. In addition to having taught as a Lecturer on Law at Harvard Law School, Dr. Rowles has been a Visiting Scholar at Harvard University's Center for International Affairs (CFIA). His fellowships include a Stanford Postdoctoral Fellowship in Law and Development, the Rómulo Gallegos Fellowship in International Human Rights awarded by the Inter-American Commission on Human Rights, and a Harvard MacArthur Fellowship in International Peace and Security. Beyond his articles in The Trenchant Observer, he is the author of two books and numerous scholarly articles on subjects of international and comparative law. Currently he is working on a manuscript drawing on some the best articles that have appeared in the blog.