When the United States first attacked a Syria airfield, Amerika was the only news source at the time to point out that this was a proxy war. Proxy war occurs when two superpowers clash by using a third country. The Spanish-American War, Vietnam War, Korean War, Granada Conflict, and Cuban Missile Crisis are all of this variety.
Currently, the USA is warning Syria not to go ahead with a purported proposed chemical weapons attack. Do we think this is bu– nonsense, made up and fabricated? Yes and no.
Assad is getting ready to end the US-sponsored rebels. These rebels almost surely exist in order to thwart Russian power in the region. Why else would a superpower create them? He is going to end these rebels by concentrating their active forces in a few areas, and then barrel-bombing them to death. Many civilians will perish, which is fine, since any pro-Assad civilians were beaten up and driven out by rebels long ago.
This means that the CIA-or-whomever loses a pet project, and worse, that Russia gets power in Syria. When looking at superpower actions, you have to use naturalistic metaphors, so this is one group of wolves driving another one away from a prime hunting ground. There is no moral dimension to it higher than that, but one is not needed; power is self-evident.
Just like in the last attack, this one is about superpowers maneuvering for dominance over strategically-important regions of the world. No one really cares if Assad gasses or barrel-blasts a few million more starving, low average IQ middle eastern zealots into oblivion. But everyone is also representing their own best interests.
As always, what seems like warlike conduct by Trump is in fact a way of staving off warfare. It could be that too much Russian weaponry is turning up in hostile hands in the middle east, or that he wants these resources not under their control. But his strong warning now means that the chances of an unintentional war later are reduced.
For example, consider Vietnam. We think the Gulf of Tonkin attack was fake; it was a pretext for war, sort of like Fort Sumter. But what if a decade before America had threatened to bomb any Russian or Chinese personnel in the area? There would be been a political event, and that is what democratic politicians hope to avoid. But it might have staved off war by making a clear communication instead of a wishy-washy one.
Trump is not wishy-washy. He needs Russia out of Syria. He also needs something else that separates the sane from the insane. Each time he does something sane, some people on the Right and Left scream and wail, and those get silently marked in the Useful Idiot category by not just Trump but most of the sane people left in America. His momentum builds and America gets closer to separation each time this happens.