Defense Secretary Ash Carter meets with Turkish Defense Minister Fikri Işik during a U.N. Peacekeeping Ministerial meeting at Lancaster House in London, Sept. 8, 2016. DoD photo by Air Force Tech. Sgt. Brigitte N. Brantley

Last week, I wrote that three recent developments involving U.S. military forces in Syria may trigger an “international armed conflict” between the United States (and its co-belligerents) and Syria (and its co-belligerents). I discussed why these actions could satisfy even a narrow legal view of what it takes to initiate such an armed conflict. Of course, a more expansive legal view—a position which is notably held by the International Committee of the Red Cross—would make this an even easier case. This topic—whether an international armed conflict already exists in Syria—has significant implications for a range of military actions (just take a look at Professor Dapo Akande’s useful post over at EJIL Talk tomorrow).

I want to drill down on one of the elements in this analysis: Turkey’s incursion into northern Syria—Operation Euphrates Shield.

I am motivated to elaborate on this point, in part, due to a criticism from Professor Deborah Pearlstein over at Opinio Juris, in which she expresses major doubt about my analysis. I believe Deborah’s criticism is unfounded. She writes:

“[T]he Turkish operation was, like all stated U.S. operations in Syria, aimed (in different ways) at various non-state actors in theater. And while Syria expressly objected to Turkey’s operation, I have found no mention of Syria’s objection to the U.S. role in the operation. In all events, there is no indication that either Turkey or U.S. forces engaged in hostilities against Syrian forces in those operations.”

Let’s break down this analysis.

First, does Euphrates Shield trigger an “international armed conflict” under common Article 2 of the Geneva Conventions, which, by definition, includes “all cases of partial or total occupation of the territory” of another State?

The facts:

(1) Turkey is reportedly in effective control (has established and exercised authority) over several villages and towns in northern Syria. A Turkish military official told CNN, “The Jarablus-Azaz line is totally under the control of FSA (Free Syrian Army) backed by coalition forces.” To get a sense of it, the territory under Turkish control reportedly includes a land mass similar in size to Rhode Island and now holds a population in the tens of thousands (see graphic from Turkey’s Anadolu Agency).

op-euphrates-shield-one-month-onAnadolu Agency photo

(2) Turkey’s operation met with strong public objections by the Syrian government. Damascus condemned the operation as a “blatant violation of the sovereignty” and called on the UN to “put an end to this aggression.” To put it mildly, the intervention lacks the territorial State’s consent.

The law:

What plausible argument is there that this situation is not an occupation under even the most conventional interpretation of the law on this topic?

Deborah writes “there is no indication that either Turkey or U.S. forces engaged in hostilities against Syrian forces in those operations.” But the plain text of Article 2 of the Geneva Conventions states that it applies “even if the said occupation meets with no armed resistance.”

Deborah also writes that the operation is “aimed (in different ways) at various non-state actors in theater.” But surely it does not matter what the reason is for Turkey to occupy parts of Syria. Even in the debate between Professors Adil Haque and Terry Gill over the general question of when CT strikes in another state’s territory constitute an international armed conflict, Terry acknowledges (as anyone would, I think): “In the event the intervening State’s action resulted in occupation of territory, this would change the situation and trigger the regime pertaining to IACs.” Notably, Adil and Terry are speaking about a situation that closely resembles Euphrates Shield—where “a State were to intervene and take control over another State’s territory, whether this was under governmental control or had been under the control of an armed group until the intervening State displaced that control and substituted its own.” In other words, Terry (a strong proponent of the narrow legal view I mentioned at the outset) and Adil (a strong proponent of the more expansive view) agree this would “clearly constitute an IAC [international armed conflict].”

Second, is the United States a co-belligerent of Turkey in these operations? Before answering that question, for many reasons, it is important to emphasize that the United States has explained that it did not support any Turkish strikes on the Syrian Kurds. However, what about the general operation to seize control over these areas of northern Syrian? Some of the best legal analysis of what actions constitute co-belligerency in contemporary conflicts is Just Security’s Nathalie Weizmann (see here, here, and here). Operation Euphrates Shield seems like an easy call along that legal front. General Joseph L. Votel, commander, U.S. Central Command, stated that the United States coordinated with Turkey beforehand and provided “air support to the operations in Jarablus.” The Pentagon’s Press Secretary confirmed that the U.S. military conducted airstrikes in support of the operation. If you’re still not convinced, read this report by ABC News—“US Special Ops Forces Working With Turks in Syria in Fight Against ISIS”—including references to public statements by Capt. Jeff Davis, a Pentagon spokesman.

Let me wrap up with three brief points.

First, while Turkey and the United States are not parties to Additional Protocol I to the Geneva Conventions, guess who is: Syria, and its partner in crime Russia. As a matter of treaty law, the Protocol—and its treaty-based prohibitions and assignment of war crime status to actions such as bombing hospitals and indiscriminate attacks affecting the civilian population—applies only if Syria is in an international armed conflict.

Second, one of the more complicated legal questions is whether Syrian (and Russian) strikes in other parts of the country would have a sufficient “nexus” to the international armed conflict (e.g., the armed conflict created by Euphrates Shield or the other recent hostilities I described in my earlier post). Turkey is reportedly working with the Free Syrian Army in northern Syria (e.g., the quote above to CNN). One question is: would Assad’s attacks elsewhere in the country against that armed group, and against civilians who support the group, have a sufficient nexus to the international armed conflict with Turkey?

Third, if Turkey is, indeed, engaged in an occupation of parts of northern Syria, Ankara must now comply with a host of legal obligations under the Fourth Geneva Convention as an occupying power. That raises a final question: what of those obligations apply to Ankara’s co-belligerents?