Why?

According to the Washington Post, apparently the U.S. is preparing to conduct a "limited" military strike -- two days of cruise missiles -- against Syrian military installations in "punishment" for the Assad regime's alleged use of chemical weapons during the ongoing civil war:

President Obama is weighing a military strike against Syria that would be of limited scope and duration, designed to serve as punishment for Syria’s use of chemical weapons and as a deterrent, while keeping the United States out of deeper involvement in that country’s civil war, according to senior administration officials. 

The timing of such an attack, which would probably last no more than two days and involve sea-launched cruise missiles — or, possibly, long-range bombers — striking military targets not directly related to Syria’s chemical weapons arsenal, would be dependent on three factors: completion of an intelligence report assessing Syrian government culpability in last week’s alleged chemical attack; ongoing consultation with allies and Congress; and determination of a justification under international law.

So much of this is so wrongheaded that it's hard to even know where to start.  

First, if we want to deter the use of chemical warfare by anyone ever as being so far beyond the pale of civilization, doesn't our response have to be overwhelming rather than "of limited scope and duration"?   Won't this just send a message that you can use chemical weapons against civilian populations, so long as you don't mind risking a couple of days of slap-on-the-risk cruise missile attacks that will be calibrated delicately and deliberately to permit you to survive, i.e., "while keeping the U.S. out of deeper involvement in that country's civil war"?   Use your sarin, take your rap on the knuckles, and a week from now it will all be over and you'll still be in charge.   Isn't that what a "limited scope and duration" response says?

Second, why are we contemplating this before we get the "completion of an intelligence report assessing Syrian government culpability"?   I don't want to sound too conspiracy-minded, but is it really beyond the pale that al Qaeda-affiliated "rebels" might martyr some civilians using chemical weapons in order to generate sympathy (and confusion) in the West and provoke a response against the Assad regime?   Could this have been staged as propaganda?   I don't know.   And, what's worse, Obama doesn't know... hence the need to wait for "completion of an intelligence report."

Third, what is this I hear about "consultation" with Congress?   Under the Constitution, Congress and only Congress has the authority to declare war.   We have slid away from that in the past half-century, to be sure.    But just ten years ago George W. Bush went to Congress and made his case for invading Iraq and got an Authorization to Use Military Force.   Why is Obama somehow above having to undertake such steps, above having to actually make his case?

Finally, if we are really looking for a "justification under international law," we're screwed.   Either the use of war's violence is justified because a national interest is at stake, or else justified morally because one side is evil (Nazis) and the other side is innocent (Jews), or both.   America should go to war when American interests are at stake, or when the morality of the intervention is so obvious that inaction would be immoral.   Here, which side is the "moral" side?   The tyrant Assad, a Ba'athist Alawite Shiite allied with Hezbollah?   Or the "rebels," who largely represent the oppressed majority Sunni population, and are allied with al Qaeda?  

If Afghanistan and Iraq and Libya and Egypt have taught us anything, it's that once the blood-dimmed tides are loosed, we don't know what rough beast will emerge to slouch towards Bethlehem.

So.... why?