The United States has absolutely no right to go to war with Syria, even if the Syrian government has used chemical weapons against its people. The United States has used chemical warfare in the past, and has done horrible things to civilians in many countries, and would surely continue to do those things in Syria.
If the United States would go to war with Syria, then they'd have to go to war with Israel as well, because the Israeli military has used chemical warfare on citizens, and the United States has used chemical weapons as recently as the war in Iraq. The Syrian rebels we're arming have also reportedly used Sarin, which is the reported weapon of the most recent chemical attack.
If we want to preserve peace, the only way to do that is to stay out of these worthless wars.