A familiar air of indecision preceded President Obama’s pep talk to the nation. The first draft of his schedule for Monday contained no plans to comment on the downgrading of the U.S. credit rating by Standard & Poor’s. Then the White House announced that he would speak at 1 p.m. A second update changed that to 1:30. At 1:52, Obama walked into the State Dining Room to read his statement. Judging from the market reaction, he should have stuck with his original instinct. “No matter what some agency may say, we’ve always been and always will be a AAA country,”...