KANSAS CITY, Mo., July 30 -- Sen. John McCain last week delivered one of his sharpest critiques yet of Sen. Barack Obama's Iraq policies, carefully reading a prepared speech that accused his Democratic rival of failing the commander-in-chief test and promoting ideas that would force American troops to "retreat under fire." But just hours after his crisp performance, the Republican presidential candidate blurred his own message with an offhand comment to a television interviewer that Obama's proposal for a 16-month time frame for removing combat troops from Iraq might be a "pretty good timetable." That seemed to run counter to...