All indications are that there has been an attack with chemical weapons on defenseless civilians in eastern Syria.
Why does Donald Trump bring Iran into this discussion? The leader of Syria is Assad and his only real defender is Vladimir Putin. Is this an effort by Trump and his new adviser John Bolton to trump up a reason to attack Iran? Attacking Iran is something Republicans have wanted to do for many years. In 2018 it was Republican candidate for the presidency, Sen. John McCain who chanted "bomb bomb bomb, bomb bomb Iran". It's not a new policy idea.
The Russians are saying it simply didn't happen. As long as they pay no price they can say anything they like. If the international community is sick and tired of this law-breaking, they can act to punish Assad and Putin.
I feel certain Donald Trump congratulated Vladimir Putin on his 'electoral victory' and congratulated Sissi because of his great win because he believes their victories are at least as great as his own.