During his second term, Donald Trump has railed against the United States’ closest allies. He has imposed tariffs, threatened to upend security commitments, and openly challenged the borders of Canada, Panama, and Greenland.

Historians often look to the past for insight about the present and future. But although alliances have collapsed for many reasons over past centuries, Margaret MacMillan argues in a recent essay for Foreign Affairs that Trump’s current behavior toward allies has little precedent. His approach, she writes, “does not suggest a clever Machiavellian policy to enhance American power; rather, it shows a United States acting against its own interests in bewildering fashion, undermining one of the key sources of that power.”

A renowned historian and professor emeritus of international history at Oxford University, MacMillan is one of the greatest chroniclers of the grand alliances of the twentieth century and the world wars they fought. She joined Editor-at-Large Hugh Eakin on August 18 to discuss the normalization of conquest and the war in Ukraine, how U.S. allies are calculating their next steps, and what the United States’ approach to its alliances will mean for the future.

You can find sources, transcripts, and more episodes of The Foreign Affairs Interview at https://www.foreignaffairs.com/podcasts/foreign-affairs-interview.

In an episode released in January 2025, Senior Editor Kanishk Tharoor spoke with the political economist Nicholas Eberstadt about the global crash in fertility rates and the looming prospect of depopulation.

Over the past century, the world’s population has exploded—surging from around one and a half billion people in 1900 to roughly eight billion today. But according to Eberstadt, that chapter of human history is over, and a new era, which he calls the age of depopulation, has begun. That subject has become even more prevalent in the past year. The United States, for example, recorded its lowest ever birthrate in 2024.

Eberstadt is the Henry Wendt Chair in Political Economy at the American Enterprise Institute and has written extensively on demographics, economic development, and international security. In a 2024 essay for Foreign Affairs, Eberstadt argued that plummeting fertility rates everywhere from the United States and Europe to India and China point to a new demographic order—one that will transform societies, economies, and geopolitics.

You can find sources, transcripts, and more episodes of The Foreign Affairs Interview at https://www.foreignaffairs.com/podcasts/foreign-affairs-interview.

In 2023, Dan Kurtz-Phelan spoke with the historians Stephen Kotkin and Orville Schell about what drives Chinese President Xi Jinping and Russian President Vladimir Putin and how they are (and are not) like Mao and Stalin.

Xi and Putin loom over geopolitics in a way that few leaders have in decades. Not even Mao and Stalin drove global events the way Xi and Putin do today. Who they are, how they view the world, and what they want are some of the most important and pressing questions in foreign policy and international affairs.

Kotkin and Schell are two of the best scholars to explore these issues. Kotkin is the author of seminal scholarship on Russia, the Soviet Union, and global history, including an acclaimed three-volume biography of Stalin. He is a senior fellow at Stanford University’s Freeman Spogli Institute for International Studies and the Kleinheinz Senior Fellow at the Hoover Institution. Schell is the Arthur Ross director of the Center on U.S.-China Relations at the Asia Society. He is the author of 15 books, ten of them about China. He is also a former professor and dean at the University of California, Berkeley Graduate School of Journalism.