On Wars and Laws
Hi friends,
This weekend I saw a photo on social media of a person protesting U.S. military actions in Venezuela, holding a sign stating, “The year just [effing] started, man.”
And that’s a whole mood.
My goal with Foundations, as always, is to lay the cornerstones of foreign policy and international law in a way that enables us to build on them during our time together. Given recent events, I’d like to do a short series on the area of international law known as the law of war, starting with the law that governs a state’s decision to resort to armed conflict.
I’ll have more on that below, but need to make one quick personal note at the outset: I started a new job this week (!!), so this seems like a good time for a reminder that the views in The Connection are my own, made in my personal capacity, and do not reflect the views of current (or past!) employers.
With that, let’s dig into this month’s topic.
What do we mean when we talk about the law of war?
Under international law, the law of war generally falls into two main categories: the law governing the decision to enter into armed conflict, or jus ad bellum, and the law governing the conduct of the participants within an armed conflict, or jus in bello. Jus in bello is also frequently referred to as international humanitarian law. Related areas of the law also include those covering nuclear nonproliferation and arms control, as well as international criminal law on war crimes and crimes against humanity.
I’m hoping to cover many of these topics in future editions of Foundations. For today, we’re going to focus on the broad strokes of jus ad bellum.
Jus ad bellum: when is it lawful to go to war?
The baseline: prohibition on the use of force
While Just War Theory, which concerns the philosophical questions underpinning when and how a state decides to go to war, has existed for some time, the explicit prohibition of the use of force by states to settle disputes is in some respects a relatively recent development under international law. The aftermath of World War I, and later World War II, provided the impetus to develop what became a foundational article of the U.N. Charter in 1945: Article 2(4), which provides, “All [U.N.] Members shall refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any state, or in any other manner inconsistent with the Purposes of the United Nations.”
The purposes of the United Nations are set out in Article 1 of the Charter, and include, in Article 1(1), “To maintain international peace and security, and to that end: to take effective collective measures for the prevention and removal of threats to the peace, and for the suppression of acts of aggression or other breaches of the peace, and to bring about by peaceful means, and in conformity with the principles of justice and international law, adjustment or settlement of international disputes or situations which might lead to a breach of the peace.”
In other words, the U.N. Charter helped shift the concept of the use of force from simply one tool among many for the settlement of disputes between nations, to an internationally unlawful act that was prohibited unless it fell under certain enumerated exceptions. We’ll turn to those now.
Exceptions: Security Council authorization
Chapter VII of the U.N. Charter covers “Actions with Respect to Threats to the Peace, Breaches of the Peace, and Acts of Aggression.” While this section also covers provisional measures and measures not involving the use of armed forces that the U.N. can employ to give effect to its decisions, it also provides for an exception to the prohibition of the use of force where other measures would be inadequate. Article 41 provides that in such a case, the Security Council “may take such action by air, sea, or land forces as may be necessary to maintain or restore international peace and security. Such action may include demonstrations, blockade, and other operations by air, sea, or land forces of Members of the United Nations.”
Exceptions: The right to self defense
The last article in Chapter VII of the Charter, Article 51, enshrines another exception to the prohibition of the use of force: the right to self-defense, which can be either individual (one state on its own) or collective (through a body such as NATO, or pursuant to a mutual defense treaty between allies). Article 51 states in its entirety:
“Nothing in the present Charter shall impair the inherent right of individual or collective self-defence if an armed attack occurs against a Member of the United Nations, until the Security Council has taken measures necessary to maintain international peace and security. Measures taken by Members in the exercise of this right of self-defence shall be immediately reported to the Security Council and shall not in any way affect the authority and responsibility of the Security Council under the present Charter to take at any time such action as it deems necessary in order to maintain or restore international peace and security.”
As you read through this language, you likely picked up on the clause “if an armed attack occurs.” As you can imagine, this language is the center of a lot of the nuance and debate around whether a state’s use of force constitutes self-defense. If you followed our coverage of U.S. military strikes on vessels in the Caribbean Sea and Eastern Pacific, you’ll recall our position that, even taken at face value, allegations that the boats contained drugs destined for the United States would not constitute an armed attack such that the U.S. was justified in using military force in response. There are, however, more complicated situations: are significant cyber attacks on infrastructure that could result in injury or death armed attacks? What if an armed attack has not been carried out, but is imminent—and just how imminent does it need to be for a preemptive use of force to constitute self-defense? You can see where the nuances lie.
Under customary international law, the use of force in self-defense has to be both necessary and proportionate, which includes an assessment of whether there are other alternatives to the use of force that could be used instead, and whether the measures are proportional to the threats being addressed.
Current developments: addressing aggression
Particularly if you have been tracking the aftermath of Russia’s invasion of Ukraine, you may have heard reference to Russia’s “aggression” or “war of aggression.” While different bodies use different definitions, the Kampala Amendments to the Rome Statute of the International Criminal Court define an “act of aggression” as “the use of armed force by a State against the sovereignty, territorial integrity or political independence of another State, or in any manner inconsistent with the Charter of the United Nations.” The definition goes on to give a number of examples of acts of aggression, including “the invasion or attack by the armed forces of a State of the territory of another State, or any military occupation, however temporary, resulting from such invasion or attack, or any annexation by the use of force of the territory of another State or part thereof.”
The Kampala Amendments define the “crime of aggression” as “the planning, preparation, initiation or execution, by a person in a position effectively to exercise control over or to direct the political or military action of a State, of an act of aggression which, by its character, gravity and scale, constitutes a manifest violation of the Charter of the United Nations.”
Last summer, Ukraine and the Council of Europe agreed to establish a Special Tribunal for the Crime of Aggression against Ukraine, which would focus on accountability for Russia’s full-scale invasion of Ukraine. If you’re interested in reading more on this tribunal, I can recommend this article by Hannah Lobel and Nema Milaninia in the European Journal of International Law.
Tying it all together
The law of war, including jus ad bellum, is an area where there are entire fields of scholarship around questions such as whether an attack is imminent or whether the use of force in self-defense is proportionate, and as such, I don’t want to falsely suggest that these questions are simple. But I do think it’s useful to provide this 10,000-foot view of what the international legal considerations are for determining whether a use of force is lawful, particularly in light of recent events. And so if I had to summarize our discussion of jus ad bellum in just one sentence, it would be this: a state must not use force against the territorial integrity or political independence of another state unless it is either authorized to do so by the U.N. Security Council, or it is acting in self-defense against an armed attack.
Now go forth and wage peace.
ICYMI
We’ve covered quite a bit in The Brief over the last month, including:
- An overview of proposed changes to the material used to vet participants in the U.S. Visa Waiver Program, and why these changes raise human rights and foreign policy concerns;
- A primer on why the military regime in Myanmar is calling elections, and why these elections are neither free nor fair; and
- A special edition on U.S. military actions in Venezuela.
Is your new year’s resolution to write more about foreign policy?
If so, let’s talk! I’d welcome guest contributors with knowledge to share on international law, human rights, or foreign policy, so if that’s you, I’d love to hear from you.
Alexis
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