The one thing I do know and am very confident about is this: vulnerability to secession does not deter other countries from recognizing an independent Kurdish state. Sorry, I know this is the conventional wisdom (as presented in this piece), but the conventional wisdom has always been wrong and always will be wrong. How do I know that? Well, see my first book, see this article, and this one, too. Perhaps notice which countries recognized Kosovo (hint: Canada). Oh, and check out Russia's foreign policy, given that it is vulnerable to secession yet have been sponsoring separatists frequently and enthusiastically. And yes, countries can be irredentist even as they face separatist movements at home.
Canada, as the story linked above indicates, that despite arming and training Iraq's Kurds, wants these Kurds to stay in Iraq. Why? Two primary reasons: a) Turkey is an ally, and Turkey fears that an independent Kurdistan in Iraq and/or Syria would strengthen the Kurdish separatists in Turkey;* b) most solutions to the Iraq political problems need the Kurds. Sure, there are folks who advocate partition of Iraq into three hunks of territory, but partition is never as easy or as beneficial as the advocates argue. Having the Kurds in along with the Sunnis to balance the Shiites might just be key ingredients in some shot of power-sharing deal. Of course, that is hard when the Shiites have been pretty committed to crushing the Sunnis (which is why the Sunnis have chosen the less bad alternative of ISIS). But in the long run, Iraq will need a political solution that is not just handing over the largest part of it
* While I am a committed skeptic about how contagious ethnic conflict can be, one of the few ways that ethnic conflict travels is among ethnic kin who are separatist. See also this.So, Canada is aiding a group but not promoting its eventual aims. Not that new, but definitely tricky. The article from the National Post makes clear that Canada has been clear to all sides about its stance. Which is the same stance as the rest of the coalition.
Of course, there is another Kurdish problem: we are sinking resources into training the Kurds, but their aims (other than independence) are quite limited. They don't want to fight to win territory that they cannot keep. And the downside of being the most reliable force in the region is that they have won most of the territory they claim. It is not clear that they can do much more to push ISIS back into Syria. Oops.
But that is why I keep calling this region the land of lousy policy alternatives. As for the Kurds, I do feel for them in a big way. They have been betrayed many times before. This time, we are being honest and using them for what we see as the greater good. And they are using us for their interests. As always, the hard part in these interventions is figuring out how to align the interests of those who live there with those of the interveners.