Alright, there's been some debate on that and I think it is a good example of why Garrison labels every goddamn thing in his cartoons. He is incapable of making things clear when he tries to be subtle.
Note the literal "Jew nose" on the skull, the skull has also been labeled as "WAR" which, I suppose, implies that the Syrian war is a Jewish plot that Trump and Putin have been dragged into unwillingly. Also there's some other symbol carved into it but I'm not sure what that is.
I originally thought that the cartoon is critique of Trump's actions but clearly the REAL culprits according to Garrison are the Jews. Don't ask why or he'll probably go on an hour rant on how Jewish cabal control the world.
Trump and Putin seem upset which implies that they didn't want the war and they are merely prisoners of the Jew-war-skull.
False flag event, which is also a flag because this is about as clever as Garrison can get also appears to imply that Assad didn't do the chemical attacks or whatever and it's just another ploy. (Possibly by the Jews.)
Syria being represented by a Syria shaped (and labeled) piece is pretty clear.
Needs more labels.