Someone correct me if I have this wrong.
We want "diplomacy" to solve the situation in Syria, but to do so we need to stand ready to lob some missiles at them. If we do lob missiles at them, it wouldn't be with the intent of altering the course of the conflict; we don't want to choose sides, after all. We just want to fire enough missiles at…something…to remind other countries that we are totally tough and capable of lobbing missiles at things from afar. I mean, we can't Show Weakness In Front Of the Russians.
Wow. Never thought we'd get to use that dusty Cold War gem again.
The technology available to modern presidents has reduced the costs of going to "war" (or "police action" or "intervention" or whatever euphemism is appropriate for not-really-wars like this) to the point that it appears to have permanently warped the judgment of our political leaders. Is there anything less costly to a president, to the Pentagon, to Congress, to the belligerent public, than parking naval assets in international waters and launching guided missiles at far-off targets? It costs no American blood and little political capital – if anything, it succeeds in making presidents look "tough" or whatever. It costs nothing but money, and god knows that we are perpetually broke but somehow always able to dig deeper into the pocketbook to find more money when the Department of Defense deems it necessary.
Combined with the use of air strikes (high altitude bombing runs against countries relying on Vietnam-era Soviet anti-aircraft defenses) and the growing popularity of drones, video game warfare is upon us. There really isn't much incentive for a president not to conduct that type of war continuously and against all perceived threats. No one weeps when a drone crashes, nor do Americans particularly care if cruise missiles aren't as "pinpoint accurate" as defense contractors claim. The only thing that rouses the public against war, in the rare instances in which that actually happens, is the cost in American lives. Remove that from the equation and the use of force can continue in the background almost indefinitely. Having declared war on a threat that can never be eliminated completely, we've found a way to remove morality from the use of force by isolating it from the only lives that matter in our political process.