JUANA SUMMERS, HOST:
Secretary of Defense Lloyd Austin is on a mission to reassure a jittery ally - South Korea. Seoul wants stronger support from the U.S. as it faces a growing North Korean nuclear threat. And as NPR's Anthony Kuhn reports from Seoul, this comes as the U.S.' decades-old system of alliances in Asia is under increasing stress.
UNIDENTIFIED PERSON: All right. It's charged. Weapon is on safe. Pull the trigger. Nothing happens. If it fires, boom. Move to the rear. Charge it.
ANTHONY KUHN, BYLINE: Soldiers of the U.S. Second Infantry Division practice assembling and disassembling their rifles close to the border with North Korea. Seventy years after the end of the Korean War, the division still defends South Korea against an invasion from the North. But a lot has changed over the past seven decades, too. Excavators dig up part of U.S. Army Garrison Yongsan in Seoul. U.S. forces are moving to a new base down south. And after more than a century as first a Japanese then an American garrison, the base is being reclaimed by Seoul and turned into a park. Yoon Choon-gyo is 85 and was born in North Korea. He fled to the South, where he worked at the base's military hotel.
YOON CHOON-GYO: (Speaking Korean).
KUHN: "It's been a long time since I retired," he says. "But I got a lot of help from Americans. And thanks to them, I could live a comfortable life." He says he's grateful to the U.S. for helping South Korea survive as a nation. Now the U.S. would like its ally to help it constrain China and sell weapons to Ukraine, both of which are likely to come up during Secretary Austin's visit. But Seoul National University historian Park Tae-Gyun says South Koreans are worried about being dragged into foreign conflicts.
PARK TAE-GYUN: (Through interpreter) The government and civil society have different ideas. And civil society seems to have a fear of South Korea's security role expanding beyond the peninsula.
KUHN: Part of the problem is that unlike NATO in Europe, where an attack on one ally is considered an attack on all, in Asia, the U.S. has only bilateral alliances. It's described as a hub-and-spoke system, with the U.S. being the hub and the allies the spokes. Mason Richey is an international politics expert at Hankuk University of Foreign Studies in Seoul. He doesn't see the hub and spokes falling apart anytime soon, but...
MASON RICHEY: What we do see is an increasing understanding that it is inadequate to the challenges. And so the strategy for trying to maintain peace and stability in East Asia relies on augmenting the hub-and-spoke model.
KUHN: Some of the spokes worry that their hub may abandon them to save itself. Last month, South Korean President Yoon Suk-Yeol suggested that if North Korea ups its threats, the South might have to get its own nukes. Texas A&M University political scientist Matthew Furman and his colleague Todd Sechser have done a statistical analysis of nuclear powers' commitments to defend their non-nuclear allies.
MATTHEW FURMAN: We found that countries that have formal defense pacts, like the ones that exist between the United States and South Korea, with nuclear armed states, are less likely to be targeted in disputes by other countries.
KUHN: So he says while South Korea may be understandably jittery that the U.S. won't use its nukes to defend them, North Korea may be even more nervous that they will. Anthony Kuhn, NPR News, Seoul. Transcript provided by NPR, Copyright NPR.