ABC News -- ABC News Rick Klein reports: We're back to discussions of war and peace. And the toll of war comes into sharper focus. The awful news out of Fort Hood, Texas, is a story that will consume all the political oxygen for a while. It will replace it with -- depending on the circumstances that develop -- fresh discussions about the physical and mental costs of war, of race and religion in the armed services, and of the nature of the sacrifices the nation asks of its troops. It comes as President Obama ponders some of the biggest foreign-policy challenges of his time in office. Troop levels have been and will continue to be a major part of that discussion. And now the nation wants to know as much as it can learn about what that means for those...