By using these banned weapons and wantonly bombarding civilian neighborhoods with conventional munitions and crude barrel bombs, Assad is collectively punishing his own people as a warning against further rebellion.
Sunni Arabs are Assad’s “own people” the way the Arabs in Mandatory Palestine were the Israelis’ own people. Not at all. That is why he gassed them - so those that who were not prepared to acquiesce in continued Alawite rule would leave Syria altogether, greatly easing the 50-year problem of recurring Sunni Arab revolts. The Alawite problem is the Sunni Arabs’ 7 to 1 numerical superiority.