Windfall is the boldest profile of the world's energy resources since Daniel Yergin's The Quest, asserting that the new energy abundance—due to oil and gas resources once deemed too expensive—is transforming the geo-political order and is boosting American power.

"Riveting and comprehensive...a smart, deeply researched primer on the subject." —The New York Times Book Review
As a new administration focuses on driving American energy production, O'Sullivan's "refreshing and illuminating" (Foreign Policy) Windfall describes how new energy realities have profoundly affected the world of international relations and security. New technologies led to oversupplied oil markets and an emerging natural gas glut. This did more than drive down prices—it changed the structure of markets and altered the way many countries wield power and influence.

America's new energy prowess has global implications. It transforms politics in Russia, Europe, China, and the Middle East. O'Sullivan considers the landscape, offering insights and presenting consequences for each region's domestic stability as energy abundance upends traditional partnerships, creating opportunities for cooperation.

The advantages of this new abundance are greater than its downside for the US: it strengthens American hard and soft power. This is "a powerful argument for how America should capitalise on the 'New Energy Abundance'" (The Financial Times) and an explanation of how new energy realities create a strategic environment to America's advantage.