What the 3 Body Problem Means for Nuclear War

“We’re not seeing yet a full-fledged, really cemented, long-lasting, resilient geopolitical alliance,” Gen. Mark A. Milley, the outgoing chairman of the Joint Chiefs of Staff, told Foreign Affairs magazine last month. “Could that happen in the future? It could, and we need to be wary of that, and we need to do what we can to make sure that doesn’t happen.”

Ardent security analysts call for quick expansions of the American arsenal. In March, the Livermore weapons lab in California published a lengthy report arguing that the buildup should begin in early 2026 as New START, one of the last major arms-control agreements between Moscow and Washington, expires. Swarms of retired warheads, the report said, should then be redeployed on missiles, bombers and submarines.

Despite proposals for Washington to match the combined forces of Beijing and Moscow, analysts say bids for weapon parity are likely to fail. That’s because Washington’s rivals would see what’s coming and, in response, would most likely expand their own arsenals.

Parity will be “continuously sought but never achieved,” as Dr. Krepinevich put it last year in Foreign Affairs. Other analysts agree. Rather than weapon equivalence, they see endless arms races whose moves and countermoves could raise the risk of miscalculation and war.

Despite the prospect of complicated new threats and uncertainties from three atomic superpowers, Newton’s bane can still offer practical advice, said Melvin G. Deaile, director of the School of Advanced Nuclear Deterrence Studies at Maxwell Air Force Base in Montgomery, Ala.

Most basically, Dr. Deaile said, it argues that the armed forces of the United States should adopt a strategy of unrelenting flexibility given the tumult to come. “Static deterrence will not suffice,” he stated in an Air Force journal. “Deterrence will have to become agile.”

In an interview, Dr. Deaile expressed confidence that the existential threats of the tripolar world could be managed successfully.