No matter what the facts are regarding use of chemical weapons in Syria it appears that the United States is about to exercise military force based on emotion, frustration, and presidential ego. The emotion comes from the images of victims of chemical weapons offered by the media. The frustration comes from the fact that we have so little influence in a civil war where the main players are authoritarian governments, religious zealots, and terrorists (including Al Quaida). The presidential ego is driven by ill advised references to "red lines" and prodding from both the political left and right.
A more rigorous framework for making the decision to go to war (surgical strikes are an act of war just as collateral damage is death) would be the Weinberger Doctrine developed by former Secretary of Defense Casper Weinberger. The doctrine states that the United States would only go to war under five preconditions: the use of force would be restricted to matters of vital national interest; political and military objectives would be specific and achievable; the public and Congress would support the war; we would fight to win; and force would be the last resort.
You can judge for yourself how possible military action by the US stacks up against the Weinberger Doctrine. You can also speculate as to the response. To think that Syria and its allies (Russia, Iran, and Hezbollah) would not respond reminds me of being told before we invaded Iraq that the war would be short, we would be greeted as liberators, and Iraqi oil would pay for the war.