Not sure, it's possible he just kneejerk reacted because he is aware that the deep state has been pushing this war with Syria and the ousting of Assad. But, it's also possible he did all this to bring more attention to the matter. Sorta like taking a hit for the (Q) team and such. Creating a fervor around a rejection of war with Syria/Russia could later help, if the massess (especially on the left) are rejecting any Trump indication of going to war. When the deep state later tries to say we need to go to war it will be difficult to make logical argument for it. Also, this deep state insistence on war or striking Syria, Trump obliged, but rumor has it that he did so after announcing withdrawal, which in effect allowed for rebels to reveal themselves and thus, Trump struck the deep states chemical weapons (it is rumored).