Thanks to Ryan Goodman for his thoughtful entry in our ongoing discussion about the existence of an international armed conflict (IAC) in Syria. For those just joining, I’d questioned Ryan’s analysis that an IAC exists in Syria as between Syria and the United States on the grounds that none of the three recent events Ryan cited in support for his conclusion – the putative existence of a U.S.-backed “no-fly” zone in country, the United States’ mistaken attack on Syrian forces (which the U.S. says it mistook for ISIL forces), and the U.S. support for Turkish operations in northern Syria – established that the United States was now a party to a conflict against Syria (any more than earlier U.S. operations had established as much). Ryan responds solely on the matter of U.S./Turkish operations in the north, arguing that an area of northern Syria is now subject to occupation by Turkey, and that the United States is a “co-belligerent” with Turkey in this occupation.
Let me begin with an area of agreement – that if one state occupies the territory of another state it triggers an IAC. Is that what’s happening in Syria? I suspect Turkey and the United States would quibble with that characterization of affairs – both Turkey and the United States have stated that the area of concern is in the control of the Free Syrian Army, who have the support of coalition and Turkish forces. But for these purposes let us assume the situation is simply a partial occupation of Syria by Turkey. The core question here with respect to the United States’ status is whether its involvement demonstrates its co-belligerency with Turkey (against Syria).
Whatever else might be said about the concept of “co-belligerency,” a model of legal clarity it is not. Ryan cites to several useful posts on the topic (in a different context) by Just Security’s Nathalie Weizmann; and Rebecca Ingber has an indispensable article on the topic as well. Two points I think especially important for present purposes. First, as both Nathalie and Rebecca explain, co-belligerency is a concept from the (pre-UN Charter) law of neutrality that has been imported into the law of armed conflict; its scope and applicability in the modern law of even IAC remains the subject of much debate and little if any authoritative guidance. Nathalie and Rebecca thus rely mostly on arguments of various scholars to unearth its meaning. That said, second, as Nathalie describes it: “Under the law of neutrality, a State will become a co-belligerent when, in association, cooperation, assistance or common cause with another belligerent it participates in hostilities to a significant extent or it systematically or substantially violates its neutrality duties of impartiality and non-participation in the conflict.”
Is the United States (and for that matter, other air forces in the “coalition” it describes as participating in the north) “systematically or substantially violat[ing] its neutrality duties of impartiality and non-participation in the conflict” by supporting a Turkish occupation of Syria? I think it is certain that the United States would strongly contest that assessment. In the DOD press conference cited in Ryan’s original post regarding the fighting in northern Syria, the Pentagon spokesman was at pains to make clear that U.S. activities in the region were exclusively focused on attacking ISIL full stop: “When they [Turkish forces] began to focus on something other than ISIL then I think we had to withdraw our support for that. And so I think we are now trying to keep those elements separated and focused on the counter ISIL fight at this point….. [W]hat we have made clear is that our support is — our support to all parties is contingent upon the focus on ISIL. And that will be how we will continue to do this.” The news stories Ryan cites on the U.S. role in the region are consistent with this statement. From this I glean not only does the United States not share common cause with Turkey to the extent of any Syrian occupation, but that the United States does not cooperate, assist, or in any other way support Turkey to the extent that state is participating in any Syrian occupation.
While I think the public reports of activities in the region are all consistent with this view, my point here could hardly be to hope to settle definitively what exactly the United States and its allies are doing in northern Syria. The open sources speak for themselves, but undoubtedly do not contain the whole story. My point is rather, as I put it in response to Ryan’s original post, I think the claim that the United States is a co-belligerent in an IAC in Syria (based on these events) is hardly clear. Given that legal uncertainty, and given what I believe (and still believe) are significant negative policy consequences that would flow if the United States decided to publicly announce it was engaged in an IAC in Syria, I would not encourage the U.S. government to pursue such an announcement.