In September, in his first address to the UN General Assembly as president, Joe Biden pledged that the United States was not “seeking a new cold war or a world divided into rigid blocs.” That pledge was echoed, in different words, by Biden’s Chinese counterpart, Xi Jinping, and reinforced by warnings from a slew of other leaders about the grim consequences of a world split into warring camps. Yet rather than offering reassurance, this chorus served mostly to highlight just how dismal the geopolitical reality has become, with suspicion and acrimony threatening to sink trust and cooperation even in the face of shared existential challenges.

Is it too late? Has a new cold war already begun? Despite some clear differences between the U.S.-Soviet contest then and the U.S.-Chinese contest now, Hal Brands and John Lewis Gaddis argue that the time has come to carefully study the lessons of the former in order to prevent catastrophe in the latter. “The greatest unfought war of our time,” they write, can “enhance resilience in a Sino-American rivalry whose future, hot or cold, remains unclear.”

In their respective essays, M. E. Sarotte and Fiona Hill explore the lost opportunities and dashed hopes of the Cold War’s aftermath: how a moment of both American triumph and new global possibility gave way to competition and disarray. Sarotte digs deep into the archives to reveal how and why Washington’s relationship with Moscow so rapidly regressed after the dissolution of the Soviet Union. Hill, reflecting on her experience as both a longtime Russia watcher and the senior Russia official on Donald Trump’s National Security Council, shows how effectively and advantageously the Kremlin has exploited American dysfunction—above all during the administration in which she served.

Finally, John Mearsheimer contends that sharpening U.S.-Chinese competition is just the latest act in what he has called “the tragedy of great-power politics.” The mystery, he argues, is not why the relationship between Washington and Beijing has so dramatically deteriorated but why Americans ever thought a different outcome was possible; now, in his view, a darker, less delusional worldview offers the best chance of averting disaster.

In the decades since the onset of what we may someday come to call the First Cold War, historians and policymakers have endlessly studied its opening moves and argued over what, if anything, could have been done differently. To invoke the Cold War parallel is not to endorse it as either desirable or inevitable. Instead, it should serve as a reminder: that now is the time to bring scrutiny, care, and wisdom to the opening moves of this new competition, before it truly is too late.

—Daniel Kurtz-Phelan, Editor