Peter Hart and Jim Naureckas have been writing great analyses here on the media's utter lack of skepticism on the administration's intelligence regarding Syria. I'd like to add that the media likewise have failed almost entirely to inform the public about the legality of a US unilateral intervention from the perspective of international law.
That Syria's use of chemical weapons violated international law has been a major argument in favor of US intervention–and echoed in the media. Why did Obama draw the infamous "red line" in the first place? Because using chemical weapons is considered so abhorrent that the international community created a special treaty to outlaw them, and the administration argues that the US needs to make sure that law is upheld and enforced. As Obama proclaimed on ABC's This Week (9/13/13):
Keep in mind that my entire goal throughout this exercise is to make sure that what happened on August 21 does not happen again. That we do not see over a thousand people, over 400 children, subjected to poison gas. Something that is a violation of international law and is a violence of common decency.
Some in the media took up the same argument, like ABC's Christiane Amanpour (This Week, 9/1/13):
And, of course, the point is, though, your question, looking at these pictures and those that you just aired just now, is there any way the president cannot give the order? And I think many of the Western governments believe there's no way. That this is not just ugly, it's unacceptable under international law, and the use of weapons of mass destruction needs to be responded to.
But if international law is so important in evaluating Syria's actions, then shouldn't it be equally important in evaluating the proposed US response? According to the UN Charter–which takes legal precedence over all other international treaties–only the Security Council can authorize the use of military force, except in the case of self-defense. In other words, without Security Council authorization, US military action against Syria would be illegal under international law.
(Note that Syria never signed the treaty banning the use of chemical weapons, which means that technically it can't be in violation of it–but a strong argument can be made that its actions violate other treaties to which it is a signatory.)
To hear US media tell it, though, only some international law matters.
In fact, the question of whether US military action would be legal is rarely raised. In a New York Times article headlined "The Basics of the Debate" (9/11/13), international law wasn't mentioned. In ABC's interview with Obama, George Stephanopoulos didn't ask about the legality of US military action. Nor did Amanpour in her report.
In the only example I could find of a network journalist raising the point, PBS's Margaret Warner (9/2/13) reported that people in the Arab League and the Egyptian government emphasized to her that "the only legal basis for military action is under either the UN charter of self-defense or by a vote of the Security Council."
When Putin made the illegality of military action the centerpiece of his Times op-ed (9/12/13), it prompted very little discussion of the point, with reaction focusing instead on how "insulted" US politicians felt by the piece (Politico, 9/12/13). "I almost wanted to vomit," Sen. Robert Menendez (D-N.J.) told CNN (9/11/13) was his reaction to Putin's comments.
There have been some scattered op-eds that have seriously discussed this issue of international law, including two in the Times. On August 28, under the headline "Bomb Syria, Even If It Is Illegal," political scientist Ian Hurd laid out a case that "Mr. Obama and allied leaders should declare that international law has evolved and that they don't need Security Council approval to intervene in Syria."
And in a September 4 column, Yale law professors Oona A. Hathaway and Scott J. Shapiro argued:
If the United States begins an attack without Security Council authorization, it will flout the most fundamental international rule of all–the prohibition on the use of military force, for anything but self-defense, in the absence of Security Council approval. This rule may be even more important to the world's security–and America's–than the ban on the use of chemical weapons.
These are both important contributions to a debate this country should be having, one that's very much happening elsewhere in the world–but US media for the most part aren't joining the conversation.