Afrin is separate canton.
Do you really want to go into that? Really? Who defined Afrin as a seperate canton? Assad? Last I checked, Afrin was part of the Aleppo Governorate in Syrian Arab Republic.
https://en.wikipedia.org/wiki/Aleppo_Governorate
How it became an autonomous region suddenly? Who defined it like that?
https://upload.wikimedia.org/wikipedia/commons/1/16/De_facto_cantons_of_Rojava.png
PYD defined it as one of the autonomous regions of a greater autonomous entity known as Rojava, which literally means "Western Kurdistan" in English. Where is the Northern part of this entity? I know where it is, but US diplomats told me to stay calm because PYD has nothing to do with Turkey.
By the way, special props to the retardedness of this organization. "Autonomous Region" inside an "autonomous region", well done.
The political entity that they all tied to is so-called Democratic Federation of Northern Syria.
https://en.wikipedia.org/wiki/Democratic_Federation_of_Northern_Syria
Democratic Federation of Northern Syria (Just like it's retarded brothers Democratic Republic of Congo, or People's Democratic Republic of Korea) is supposed to be a multi-ethnic, ultra democratic, third wave feminist autonomous region inside Syria. Whereas in reality they don't even bother using that name and instead use Rojava (Western Kurdistan), which doesn't mean anything to the international audience, but means a lot to Turkey.
So, here is the political entity, here is the land it claims authority on, here is the obvious future vision from it's name. Now let's take a look at what US says?
We don't support Kurdish forces in Afrin. Kurdish forces in Afrin are affiliated with YPG, are part of PYD, also part of the political entity that is so-called "Democratic Federation of Northern Syria". So when USA helps Kurdish groups in the Eastern areas (including Manbij), make up some other name for them called as SDF (Syrian Democratic Forces), does that really mean USA does not really help Afrin?
As far as I concern, after the Euphrates Shield operation, Afrin canton couldn't merge into broader PYD area and became isolated. Since entire US narrative regarding SDF support is completely based on "fighting against ISIS", there was no legitimate reason to directly arm or train those left in Afrin. So they had to cut another deal with Russians, called them as protectors against a Turkish attack. That neither makes them a separate entity, not it makes sense to claim that the weapons or the training that US provided to the eastern part of this retarded region, would not diffuse into Afrin. That being said, there is no political difference between Afrin and the rest of that SDF region, so Turkey will have to target all of them.
Don't reduce the threshold for "supporting terrorism". Your country also have a struggle against terrorism and you wouldn't want some smart-*** diplomat come to you and say "Oh I didn't give any arms to the ones in this region, I only helped them in that region". That really doesn't mean anything on the field. The guy you train in Manbij goes Afrin. The weapons you gave in Raqqa ends up in Afrin. Arguing that obvious facts means actively trying to fool people.