President Obama will address the nation on Tuesday about an attack on Syria. Today, in Russia, he declined to say what he would do if Congress fails to give its approval. He did however emphasize that, "I think we will be more effective and stronger if, in fact, Congress authorizes this action. I'm not going to engage in parlor games…about whether or not it's going to pass, when I'm talking substantively to Congress about why this is important." Aaron Blake covers national politics for the Washington Post.