It's difficult for an American president to govern through nuance, especially when it's necessary to persuade a majority of the people that certain actions are essential for national security. And effective persuasion usually requires clarity.
That's how you arrive at President George W. Bush's stark formulation "You're either with us, or you're with the terrorists" after Sept. 11, and much of what sprang from it.
Many school safe rooms, like this one inside Jeffries Elementary in Springfield, Mo., also serve as gymnasiums. Constructed with a $1.6 million grant from FEMA, which covered 75 percent of the cost, the shelter can hold more than 500 people — enough to accommodate all the school's students and employees.