As the US presidential campaign enters its final stage, we are on the point of a major debate about America's role in the world. Barack Obama and Hillary Clinton were rivals who became partners for a time, trailblazers who share a common sense of their historic destiny but different instincts about how to project power. As one prepares to relinquish the presidency, and the other makes her long-awaited bid for it, how Hillary Clinton and Barack Obama regard America's role in the world is a central question of our time.

Mark Landler, White House correspondent for the New York Times, offers a deeply reported, first-hand account of the complex relationship between these two leaders and gives us a different way to think about Obama's legacy and Clinton's promise. With all the sweep of a grand history, enlivened by an insider's access, dozens of interviews, and breaking news, ALTER EGOS is essential reading for anyone seeking to understand these two supremely ambitious figures, and the storm-tossed world of modern politics.