A detailed account of the foreign-policy landscape that confronted the incoming Obama administration, tracing how wars in Iraq and Afghanistan, nuclear proliferation, terrorism, economic turmoil and rising powers constrained American options and shaped high-stakes choices; the book examines the policy debates, intelligence assessments and institutional limits that forced tradeoffs between diplomacy and force, and argues that the legacy of prior decisions would define the scope and character of U.S. power in the 21st century.