Globalization is over. With US president Donald Trump pursuing an 'America First' agenda in trade and foreign policy, everyone now recognises the urgency of defending their own country's national interest. But what is the national interest and why did it disappear from the political agenda? Will Trump restore American national interests, or will he betray them? How might we know the difference? The National Interest answers these questions. It explains how and why globalist political leaders and bureaucrats abandoned the national interest over the past thirty years. Even today, many of our elites still sneer at the concept as an anachronism in an age of global environmental collapse and 'polycrisis'. But without it, there can be no political representation, and without representation there can be no democratic accountability. The national interest can be revived as part of a strategy of nation-building and national rebirth. This book makes the case for such a revival, heralding a new era of democratic renewal and international cooperation.