Are prospects for global stability and prosperity improving or deteriorating? With enlightenment and progress in some parts of the world accompanied by atavism and stagnation elsewhere, this is not an easy question. But we can gain greater purchase on it by considering three other questions.

The first is whether the United States will regain its standing as a source of moral leadership. Despite its flaws, America did provide such leadership, beginning at the end of World War II. But the terrorist attacks of Sept. 11, 2001, changed everything.

Americans' anger following the attacks drove them to support policies that they once would have considered inconceivable. In the name of the "global war on terror," they have tolerated torture; accepted — and even endorsed — the illegal invasion of Iraq; and allowed innocent civilians to become collateral damage of mechanical drone strikes.