Canadian media today is reporting on a new "foreign fighter" issue: Canadian Armed Forces veterans fighting with anti-ISIL forces (such as Kurdish fighters). As is quickly the case, attention has turned to "is it legal to do so". I had a few minutes this afternoon to jot down the key legal issues, which I reproduce in this post.
To cut to the chase, in Canadian law, who and how you fight determines whether fighting in foreign armed conflicts is legal.
No Real Neutrality Law
To start at the beginning, Canada's 1937 Foreign Enlistment Law is hardly an impediment. After doing some searching in the context of an article I have written, I was unable to find a reported conviction under it. And its 1937 origins show in its antiquated language.
The Act criminalizes service by a Canadian in a foreign armed force at war with a friendly foreign state. And it creates related crimes, such as leaving Canada to join this foreign armed force fighting a friendly foreign state and a somewhat broader recruitment offence of recruiting persons to serve in (any) foreign armed force.
Armed force of a foreign state includes state armies but also would reach the armed wing of an entity "assuming to exercise the powers of government in or over any foreign country, colony, province or part of any province or people" -- so a rebel government controlling territory could be included. But not every insurgency & guerrilla group will meet this "assumption of power of government" standard. (This aspect of the law has elicited criticism of the near identical UK version of the Act -- it means that fighting for most insurgencies is unregulated by the Act).
Ok, so this means: no fighting for a state military (or a rebel movement that exercises governmental power over a territory) that is fighting against a "friendly foreign state". Not sure what the latter means, but it presumably is any state with which Canada is not itself engaged in hostilities. But for reasons tied to how we typically approach state sovereignty issues, it also presumably does not include rebel movements, unless Canada has embraced them (a rare occurrence). So fighting against a rebel movement, even one that holds territory, is not fighting against a "friendly foreign state".
But that doesn't mean that the world is your oyster if you're inclined to take up arms to fight a rebel army. It is a crime in Canada to, among other things, "knowingly participate in or contribute to, directly or indirectly, any activity of a terrorist group for the purpose of enhancing the ability of any terrorist group to facilitate or carry out a terrorist activity". A terrorist group may be a terrorist group because it is listed as such, or because one of its purposes or activities is facilitating or carrying out any terrorist activity.
"Terrorist activity" includes causing death or bodily harm by violence, for a religious, political or ideological purpose with the intention of, among other things, compelling a public, government, organization or even a single person to do or refrain from doing any act.
A rebel army can be a terrorist group. If you fight for ISIL, you've got problems. ISIL is a listed terrorist entity. And if you intentionally start shooting on behalf of ISIL, you are knowingly contributing to its activities. Along the way, it is hard to see how you don't also knowingly enhance its ability to conduct its political/religious/ideological conflict that visits harm on others and which is done, at the very least, to compel someone to do something.
It shouldn't be assumed, however, that in joining a militia that fights against ISIL, you are somehow exempted from these sorts of considerations. A militia fighting ISIL may have a different political/religious/ideological objective (and one that is generally more palatable). But it is still running around killing people in order to get someone to do something, and so it could well be engaged in a "terrorist activity". And if in joining, you intend to enhance its ability to get the job done, you may have criminal exposure.
Everything then turns on the "armed conflict" exemption in the definition of "terrorist activity" -- the latter "does not include an act or omission that is committed during an armed conflict and that, at the time and in the place of its commission, is in accordance with customary international law or conventional international law applicable to the conflict, or the activities undertaken by military forces of a state in the exercise of their official duties, to the extent that those activities are governed by other rules of international law."
So to clear, this provision basically means a state military can never commit a terrorist activity under our law. And a non-state armed force may also be excluded if it complies with international humanitarian law.
But if it doesn't so comply, the exemption from the terrorism concept is inapplicable. ISIL is killing non-combatants with abandon and is in clear non-compliance with IHL. But I for one would not assume that the anti-ISIL militias are or will always be squeaky clean adherents to IHL. Few informal armed groups are.
So to sum it up: you join the Fighting Against ISIL Brigade as a volunteer. You probably don't have problems under the Foreign Enlistment Act. But you may have problems if it turns out that members of Brigade you are knowingly supporting in shooting at ISIL is itself somewhere along the way, say, shooting at civilians.
I have been puzzling over what you must actually intend. I think it may be enough that you intend to help with the overall shooting -- that is, knowingly helping out in visiting bodily harm on "bad guys" for a group whose political motive is driving the bad guys away and is using force to compel them to go away. So you have all the intent necessary for the terrorist offence that is tied to terrorist activity. What remains is whether what would otherwise be terrorist activity is exempted by the armed conflict exemption. And whether this exemption applies or not should be a "objective fact" that is independent of your intent. So you may not intend that along the way, some of that shooting is directed at civilians. But that very fact still removes the safe harbour of the armed conflict exemption. At any rate, I don't think that the little Canadian courts have said on the exemption really clarifies this intent issue in the scenario we are discussing.
Your Own Conduct
And finally, it should be noted that whatever your criminal exposure for going into battle with potentially shady characters, you are culpable for your own war crimes and crimes against humanity under the Crimes Against Humanity and War Crimes Act. And also for your own conduct that could be construed as terrorism -- including hostage taking as Mr. Ribic discovered after his service with the Bosnian Serb army.
Terrorism offences, war crimes, crimes against humanity are all "extraterritorial offences" -- here, Canada's criminal law follows its citizens abroad.
And so ends my 30 minute analysis. My 40 hour analysis would assuredly be more nuanced, but must await the availability of 40 hours.