Robert Service's Comrades! tells the story of world communism -- but leaves the reader still hungry for explanations of why the movement lasted so long and what, if anything, it accomplished.

After Iraq, we may be tempted to turn inward. That would be a mistake. The American moment is not over, but it must be seized anew. We must bring the war to a responsible end and then renew our leadership -- military, diplomatic, moral -- to confront new threats and capitalize on new opportunities. America cannot meet this century's challenges alone; the world cannot meet them without America.

Globalization has brought huge overall benefits, but earnings for most U.S. workers even those with college degrees -- have been falling recently; inequality is greater now than at any other time in the last 70 years. Whatever the cause, the result has been a surge in protectionism. To save globalization, policymakers must spread its gains more widely. The best way to do that is by redistributing income.