Well of course in a war where the death toll is something like 200 000 dead Saa soldiers( many beheaded as prisoners), 200 000 dead Islamist extremists and 100 000 dead civilians, this is barely a drop in the ocean. Many are suggesting though that if the US strikes it may be several volleys of hundreds of missiles each. That may be enough to allows turkeys merry band to attack from the north, Isis and non Kurd sdf groups to attack from east and islamists to attack from south, and have a significant impact.I suppose it's a chance but it's a super high risk strategy when Trump has already shown he's not interested in using US troops as anything other than intel, training and air targeting. There would need to be a major US ground force to tip the balance of the war, air strikes at this stage are just about show as the various southern rebel groups don't have anywhere near the strength to go on the offensive. As far as I understand it, the US has long given up on overthrowing Assad and are holding parts of Kurdish Syria as a bargaining chip for peace talks.
It's a sectarian war, never underestimate the centuries old hatreds and fears this war has brought to the surface and in the overall scheme of civilian casualties attributed to Assad's forces from the war, this is pretty minor.