This war is not about pride or chemical weapons. It is about weakening Iran & Russia's power over $170 trillion of Mideast oil & gas. Everything else is political game-play.
It is about obama's vanity and nothing else. It was obama's foolish red line comment. That comment was made during the presidential campaign where he felt compelled to appear more presidential and in command. He was quite willing to ignore the chemical attack UNTIL he started being mocked and that comment brought up to haunt him. When people started laughing at him "what cha gonna do NOW big boy", he lashed out in the worst possible way.
As was reported in the LA Times:
Syria chemical weapons response poses major test for Obama - Los Angeles Times
One U.S. official who has been briefed on the options on Syria said he believed the White House would seek a level of intensity "just muscular enough not to get mocked" but not so devastating that it would prompt a response from Syrian allies Iran and Russia.
obama just didn't count on being pushed into a corner where his pride would be weighed against WWIII.
This isn't about oil or gas. This is about totally humiliating and annihilating obama personally and harming the power and credibility of the United States generally. This is chess, this is what global brinksmanship looks like. obama is outclassed. We let him be outclassed by artificially inflating his ego. Now it's the ego that can eat the world.