I know I'm a little late on the Syria post, given some of the recent news that might diffuse the situation, but I think a word or two is still in order.
First, should we take military action in Syria? No. I'm not saying this from a "look at the polls" perspective, though the overwhelming distaste of the American public should say something to the administration. I'm saying this from a realpolitik perspective. Attacking Syria serves no national interest of the United States. In fact, attacking without international support (more than "moral support" from some nations) and direct opposition from international giants like Russia could hurt US interests abroad.
Syria is in a civil war. Interjecting ourselves has a real possibility of destabilizing the Middle East further, depending on the reaction any military incursion might illicit from Iran and Russia. Just because the Syrian government used chemical weapons during the fighting does not mean we should be supporting the other side-who might not be squeaky clean on the weapons front either. This is not a case of enemy-of-my-enemy-is-my-friend.
Second, how can those who supported the invasion of Iraq be against intervention in Syria? Easy, in Iraq there was a UN mandate telling Hussein that military repercussions were available if he continued to stall and delay weapons inspectors. I can elaborate further on this aspect, if readers so desire.
For further reading go here, here, and here.
Edit: I'd also like to add Putin's NYTimes Op Ed as required reading.