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.

In a recent essay in Foreign Affairs, the scholar and former U.S. official Ashley J. Tellis makes a provocative argument about India’s foreign policy. In a piece titled “India’s Great-Power Delusions,” Tellis argues that Indian policymakers have their priorities wrong. Instead of pushing for what they call “multipolarity” in the international system, Indian leaders should align more closely with the United States. Tellis insists that India will be able to fend off China, its far stronger rival in Asia, only with U.S. backing. But it may lose that support if it continues to express skepticism about U.S. leadership and courts U.S. adversaries.

Tellis’s essay has provoked huge debate—in Washington, in New Delhi, and in the pages of Foreign Affairs. In this episode, Dan Kurtz-Phelan brings Tellis into conversation with two of his critics: the former Indian foreign secretary Nirupama Rao and the analyst Dhruva Jaishankar. Kurtz-Phelan spoke with them on July 25, a few days before the Trump administration announced 25 percent tariffs on India, the latest twist in ongoing negotiations with New Delhi over a new trade deal.

Tellis, Rao, and Jaishankar debate India’s pathways to power in the September/October 2025 issue of Foreign Affairs. Their disagreements touch not just on the directions of Indian and U.S. foreign policies but also on the very nature of international order in the twenty-first century.

For decades, Joseph Nye was one of the true giants of American foreign policy. His career, in government and in the academy, spanned epochs, and his body of work as a scholar of international relations remains unparalleled.

Nye, who passed away at the age of 88 in May, served in the Carter and Clinton administrations and headed the Harvard Kennedy School for nearly two decades. But he may be best known for his contributions to the study of international relations. Nye coined the term “soft power” and co-authored Power and Interdependence, a pathbreaking analysis of geopolitics, with Robert Keohane.

Fifty years later, Nye and Keohane, longtime colleagues and friends, reunited for a final time in Foreign Affairs’ pages, to argue that President Donald Trump’s single-minded fixation on hard power risks weakening the real sources of U.S. strength. It is a fitting, if not exactly valedictory, culmination of a life in the American century.

Over the decades, Keohane got to know Nye the thinker and Nye the man better than almost anyone. Dan Kurtz-Phelan spoke with Keohane about Nye’s legacy and about what a changing American foreign policy will mean for the future of international relations.

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

It wasn’t long ago that both heads of state and prominent policymakers could speak seriously about a world without nuclear weapons. But in the course of just a few years, nuclear concerns have come back in force. Arms control has broken down almost entirely. China has started a massive expansion of its arsenal, putting basic assumptions about deterrence in doubt. Vladimir Putin has threatened nuclear use in Ukraine—threats that were taken very seriously by American officials. And proliferation risks have grown, with regard to both American adversaries like Iran and American allies in Europe and Asia who may no longer trust security commitments from the United States.

Vipin Narang and Pranay Vaddi until recently oversaw nuclear policy in the Pentagon and on the National Security Council. In a new essay for Foreign Affairs, they call the situation nothing short of a “Category 5 hurricane.” And for the United States, that means putting nuclear strategy back at the center of foreign policy.

Editor-at-large Hugh Eakin spoke with Narang and Vaddi about this changing nuclear landscape and what the United States must do to survive this new nuclear age.

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

For all its promise of disruption, Donald Trump’s first term as president transformed American foreign policy less than most critics feared and some supporters hoped. Alliances held up, the rules-based order largely endured, and American global leadership appeared resilient. When Joe Biden was elected president in 2020, he could proclaim “America is back” and proceed with a foreign policy that was in many ways quite traditional.

But Trump’s second term has been different. In just a few months, he has broken with decades of precedent on everything from trade to alliances. And as Rebecca Lissner and Mira Rapp-Hooper argue in a new Foreign Affairs essay, this time there will be no going back. Trump’s presidency will fundamentally change American leadership and global order.

As senior officials on Biden’s National Security Council, Lissner and Rapp-Hooper helped chart the way forward after Trump’s first term. They argue that the task now is to understand and, in a few regards, learn from the consequences of Trump’s disruption. Contending with the world after Trump will be a tall order. But they also see it as an opportunity: a clean slate on which to write the future of American foreign policy.

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

For years, U.S. presidents have complained that European governments spend far too little on their militaries, leaving the United States to pick up a disproportionate share of the tab for the transatlantic alliance. But in the past few years, Europe’s defense spending has exploded.

At the NATO summit last week, U.S. allies committed to spending five percent of GDP on defense. That’s far more than the two percent target U.S. policymakers long called for. It’s even more than the United States itself spends on defense—the result of both escalating pressure from U.S. President Donald Trump and escalating threats from Russian President Vladimir Putin.

But Celeste Wallander, until recently the top defense official overseeing U.S. policy toward Europe and Russia, warns in a new Foreign Affairs essay that this transformation will have more complicated consequences than most Americans expect. A more capable Europe will also mean a more independent Europe, more willing to defy U.S. priorities and make demands for cooperation.

Wallander has been a key player in the transatlantic alliance as a top official on the National Security Council and in the Pentagon, including as assistant secretary of defense for international security affairs during the Biden administration. She is now executive director of Penn Washington and an adjunct senior fellow at the Center for a New American Security. The United States, in her view, will have to take a very different approach to the transatlantic alliance—at a time when it’s as vital as ever, in Ukraine and beyond.

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