U.S. Secretary of Defense Donald Rumsfeld has just concluded a quick tour of Northeast Asia. Mr. Rumsfeld is a relatively infrequent visitor to this part of the world, so his trip provides insight into U.S. thinking about security concerns in the region. In particular, the secretary's "frank" discussions in Beijing underscored regional anxieties about China's military modernization program. Although they believe such concerns are unfounded, Chinese leaders must heed the worries of their neighbors.

It was Rumsfeld's first visit to China since he took office in 2001. Security officials in both the United States and China are wary of each other. Americans (and others) fear that China has embarked on a military buildup that is disproportionate to the threats the country faces, and could therefore only be designed to establish the country over time as the dominant regional power. For their part, Chinese counter that U.S. complaints and other actions, such as strengthening its alliance with Japan, are designed to contain China and prevent it from developing into a regional and global power.

Plainly, both countries need more opportunities to explore each other's thinking, views and perspectives on national security issues. By all accounts, this trip did just that. Mr. Rumsfeld challenged the purpose of the Chinese buildup, complained about Beijing's expanding arsenal of ballistic missiles and their new capabilities, and questioned the recent call, backed by China, for the U.S. to withdraw its forces from Central Asia while the war on terrorism continued. Chinese officials defended their country's military modernization effort and dismissed U.S. estimates of Chinese defense spending as inflated and inaccurate. They also argued that the U.S. position in Central Asia and its long-term intentions toward the region were unclear.