Editor’s Note: The following is part of TNI’s special 30th anniversary symposium. We asked twenty-five of the world’s leading experts: What is the purpose of American power? You can find all of their answers here. You can also find our exclusive interview with Henry Kissinger here.

The primary purpose of American power should be to “preserve the U.S. as a free nation with our fundamental institutions and values intact.” This sturdy one-liner from the Cold War captures the big idea. It also reminds us of our too-often-forgotten yet most vital national interest. In the twenty-first century, such a bold assertion of “America First”—without apology—offends many postmodern sensibilities. For many U.S. citizens today, “American leadership” means serving as a global 911, defending those unable or unwilling to defend themselves, bearing any burden, paying any price. Abroad, any intimation that Americans at home should come first invites criticism for short-sighted selfishness unworthy of a great power.

But brute facts are hard to deny: the survival and success of the United States as a free nation is the essential prerequisite for America’s power being applied to achieve any larger objectives in the world.

Having paid the price in blood and treasure of two world wars in the first half of the twentieth century, leaders we now revere as “wise men” knew that withdrawal to Fortress America could no longer assure Americans’ survival and well-being. A new international environment required nothing less than a new world order. Their grand project combined enlightened self-interest with lofty ideals of a people whose Declaration of Independence claims for all human beings basic rights “endowed by their Creator.” It also called for mobilization of all dimensions of American power. In a unique surge of imagination and initiative, these pragmatic visionaries created the Marshall Plan (to rebuild Europe); the International Monetary Fund, World Bank, and the General Agreement on Tariffs and Trade (to provide basic economic order); NATO and the U.S.-Japanese alliance (to ensure that what they saw as geostrategic centers of gravity became pillars of international security); and the United Nations—all building blocks of an emerging global order. This order aimed to advance the cause of peace, prosperity and freedom for all—Americans, their allies and other nations, in that order.

The past seven decades of great-power peace, unprecedented economic growth and unparalleled expansion of freedom bear testament to the foresight and courage of these statesmen. Since the end of the Cold War, American policy has too often lost its grounding in American national interests. As we address challenges posed by Russia, China, the Islamic State and others, Americans should study the strategy of the “wise men” and try to follow their lead.

Graham Allison is director of the Harvard Kennedy School’s Belfer Center for Science and International Affairs and a former assistant secretary of defense for policy and plans.