In this image made from video of a still image broadcasted by North Korea's KRT on Thursday, North Korean leader Kim Jong Un, equipped with binoculars, supervises a rocket launch test. (Associated Press)

Only South Korea and Japan can heal their current rupture and overcome the historical issues that divide and distract them from focusing on a cooperative, forward-looking bilateral relationship [“Kim’s recent missile tests up the ante for Trump,” news, Aug. 2]. The United States has a deep stake in northeast Asia and must play an active and constructive role in fostering healthy Korean-Japanese relations. Korea and Japan are both treaty allies with the United States. Our defense interests are closely linked, and it is crucial that our militaries work together as we face the North Korean denuclearization challenge. Our economies are also inextricably intertwined.

The prosperity that the United States, South Korea and Japan share depends on expanding trade ties and maintaining a rules-based economic order free of political interference and tenuous national security concerns. It is urgent that our key allies in northeast Asia find common ground before their deteriorating relations cause irreparable strategic and economic damage.

Thomas Byrne, New York

The writer is president of the Korea Society.

Thomas Hubbard, New York

The writer is chairman of the Korea Society and former U.S. ambassador to the Philippines and South Korea.

Read more letters to the editor.