My friend Oona Hathaway penned an important post (“Recent Israeli Strikes on Syria and the Prohibition on the Unilateral Use of Force”) where she rightly express concern about the legal basis for a recently reported Israeli strike against a Syrian arms depot near Damascus. The strike was apparently taken to prevent weapons from falling into the hands of the terrorist organization Hezbollah.

Initially, Oona says that “Israel’s attacks appear to be on very thin legal ice under international law,” but, by the end of her post, she goes a step further and says the “Israeli strikes over the past year may be a sign that the Trump administration is willing to tolerate actions by allies that violate the UN Charter,” suggesting the United States could be tolerating Israel’s commission of the crime of aggression. In coming to that conclusion, she brilliantly summarizes, but ultimately rejects, an argument I made about a previous Israeli strike against Hezbollah as being possibly justified by the legal concept of anticipatory self-defense. (Minor point: Oona generously titles me a retired “Lt. Gen.,” but actually I’m a retired major general, which is a lower grade.)

I stand by my previous argument, but recognize that facts do matter, and more facts could strengthen my theory to the point where it is dispositive (or raise other legal justifications, including possibly having authority under international human rights law. Of course, new information could also raise further questions about Israel’s legal justification for these strikes.).

Conversely, the dearth of facts leads me to disagree with Oona’s conclusion that the U.S. could be tolerating a possible violation of the U.N. charter by Israel. Suggesting a nation – and its honorable military – is essentially committing the crime of aggression is an extremely serious matter, and something I do not think should be done absent better information than is now available. And, no, I don’t think the burden is on the accused to prove its innocence, but rather on the accuser to prove criminality beyond a reasonable doubt.

But what really surprised me was Oona’s rejection of ceasefire or, more formally, armistice, as an extant concept under international law. Relying on the very interesting but controversial new book, The Internationalists: How a Radical Plan to Outlaw War Remade the World, which Oona wrote with Scott J. Shapiro, she dismisses an argument made by Ernesto Sanchez in an Opinio Juris post last June that contends that the Israeli strikes were lawful since “the conflict between Syria and Israel that began with the 1967 war never came to an end.” Since the “UN-brokered cease fire at the close of that conflict” never matured into an actual peace treaty, the strikes are legally justified as part of an ongoing conflict, Ernesto argued.

He explains:

Moreover, Hague Regulation 36, which again used the term “armistice” to denote what is today viewed as a cease-fire, states that if the duration of an armistice/cease-fire is not defined, “the belligerent parties may resume operations at any time, provided that the enemy is warned within the time agreed upon, in accordance with the terms of the armistice.” Neither the 1967 nor 1973 U.N. cease-fire resolutions, nor the 1974 disengagement agreement, established a duration for the cessation of hostilities between Syria and Israel. And neither document addresses the issue of warning that a cease-fire denunciation is imminent.

But, according to Oona, Ernesto’s argument about the continued application of armistice law “fails to hold up.” She writes:

The key problem is that it assumes that states continue to have the right to launch attacks at one another as long as there is a “state of war.” This is an outmoded way of conceptualizing jus ad bellum. As Scott Shapiro and I show in our book, The Internationalists, war once was a legal and legitimate means of resolving disputes. But that’s no longer true. The mere existence of an official state of war is no longer a justification—by itself— for the use of force. Today, states may only use force “against the territorial integrity or political independence of any state” for reasons authorized in the UN Charter framework:

1) If the use of force is authorized by the UN Security Council.

2) As an exercise of “the inherent right of individual or collective self-defence if an armed attack occurs against a Member of the United Nations,” as recognized under Article 51 of the charter.

3) Where the host state consents to the use of force (such a use of force does not violate Article 2 in the first instance because it is not “against the territorial integrity or political independence of any state”).

While I believe that it is fair to question the effectiveness, extent, and even existence of a ceasefire or armistice in a given circumstance (to include Ernesto’s view as to its applicability to the Israeli strikes), I nevertheless disagree with Oona’s broader suggestion that international law does not provide for them.

Evidently, Oona rejects as legally “outmoded” the idea that belligerent parties to a ceasefire or armistice can “resume operations at any time” subject to whatever notice or other terms they agreed upon. To the contrary, she seems to be affirmatively insisting that once a ceasefire or armistice takes place, military operations may not “resume” even if the mutually agreed upon time period expires, or the agreed upon terms are breached. Instead, she would require a fresh showing of the same kind jus ad bellum criteria that would be necessary if no conflict had been underway. Thus, it seems that in her view the traditional understanding of ceasefires and armistices is now “outmoded” under international law.

I disagree. Consider, for example, that in its discussion of armistice, the International Committee of the Red Cross gives no hint that it’s diminished as a legal concept. The ICRC echoes Ernesto’s discussion in its description of an armistice as:

A military agreement suspending active hostilities between the belligerents. An armistice can be local (i.e., suspend operations in just one area) or general (i.e., suspend all operations). If the duration of the armistice is not defined, the belligerent Parties may resume operations at any time, subject to previous warning in accordance with the terms of the armistice. An armistice does not put an end to the state of war, which subsists with all its legal consequences. (Emphasis added).

Plainly, Oona’s view of the limitations on a party’s legal authority to resume using force simply does not track with the ICRC’s interpretation. What it takes to resume hostilities at the expiration (or breach) of a ceasefire/armistice agreement is not necessarily conterminous with the more demanding requirements of jus ad bellum. The UN framework Oona describes is what justifies initiation of hostilities, but once hostilities are underway, ceasefires or armistices are better viewed as military matters governed by jus in bello. The criteria for the use of force within an ongoing armed conflict is markedly different from that employed in a jus ad bellum analysis.

Furthermore, the Department of Defense’s Law of War Manual references the terms hundreds of times, and discusses “Armistices and other Cease-Fire Agreements” in some detail. Among other things, the Manual points out that armistices may “may persist for a long time” and says: Armistice as a Suspension of Hostilities and Not a Peace Treaty. An armistice is not a partial or a temporary peace; it is only the suspension of military operations to the extent agreed upon by the parties to the conflict. War as a legal state of hostilities between parties may continue, despite the conclusion of an armistice agreement. In some cases, however, armistice agreements may be intended to be a prelude to peace treaties. In some cases, armistice agreements may persist for a long time. (Citations omitted; emphasis added.)

For its part, there is no indication that the UN considers armistices “outmoded,” as Oona seems to suggest. In fact, it maintains the United Nations Command Military Armistice Commission for the express purpose of supervising “the Military Armistice Agreement between North and South Korea along the 151-mile-long Demilitarized Zone.”

In my view, it would be inimical not just to the law of war, but to international order, generally, if ceasefires and armistices became “outmoded” and legally unavailable to those waging war. Sure, the ceasefire Ernesto references dates to 1967, but there can still be innumerable instances where military commanders on both sides of a conflict want to temporarily suspend operations for humanitarian purposes such as retrieving the wounded, burying the dead, or allowing relief supplies to reach civilians caught in the midst of the fighting.

If an armistice or other ceasefire agreement became, as Oona seems to suppose, tantamount to a peace treaty where hostilities could be lawfully resumed only under circumstances where a new finding of a jus ad bellum rationale is established, the incentive (not to mention the authority of a military commander to conclude) to have a cease fire – even to negotiate a permanent peace treaty – disappears. Why would such a restrictive construct of international law be a desirable outcome?

To me, the principle of humanity requires permitting a cessation of hostilities by mutual agreement for any period, to include cases where it is explicitly agreed that hostilities will resume at a prescribed time despite the absence of a new basis under jus ad bellum. To say that such agreements that have proven to provide some respite from the suffering of war – even temporarily – are “outmoded” is simply wrong and counterproductive.

Determining whether armistices and ceasefires are “outmoded” tools of international law is no mere academic diversion. As I’ve discussed previously (“Assessing the legal case for the use of force against North Korea: is “armistice law” a factor?”), the international legal community may need to come to grips with the issue sooner rather than later. If Oona’s view prevails, it will – paradoxically – diminish or even eliminate agreements that can be a vital step towards the pacific international order that I know Oona, and all of us, so fervently want.


Image: Uriel Sinai/Getty