Throughout the seven decades since the founding of NATO, commentators have proclaimed that the alliance is in deep crisis. Most also combine this warning with a call for deeper “cooperation,” often a euphemism for the orthodox position that the Europeans should bear more of the burden. A critical minority, mostly on the extremes of the European political spectrum, has long complained that the United States bullies, exploits, and sometimes even subverts its European allies. This slim volume by a diplomatic historian advances a more balanced claim, based on the premise that it is natural for even the closest of allies to have serious disputes. Contrary to the conventional wisdom, the overarching trajectory of transatlantic relations has been positive: during the Cold War, NATO countries were far more bitterly divided politically than they have been since it ended. The same is true of transatlantic economic relations. This book becomes less nuanced and less empirically grounded as it approaches the present: in discussing the current challenges that populism and the pandemic pose, some of the old rhetoric of NATO’s eternal crisis returns. Yet in the end, the long historical record leads the author to view with optimism the future of the Western alliance.