In recent months, China's security policy has enjoyed significant successes. Relations with the United States have improved, particularly on issues related to North Korea. The mainland's generally relaxed approach toward Taiwan apparently has also paid dividends for Beijing by helping to solidify domestic resistance in Taipei to the purchase of weapons systems on offer from the United States since April 2001. Beijing, however, still has dangerously tense relations with Japan over disputed maritime claims that have implications for energy resource exploitation and control of sea lines of communication. These disputes, especially in the context of tensions over Japan's treatment of its wartime history, threaten to destabilize great power relations in the region and undercut China's efforts to promote itself as a power whose rise will only bring peace to East Asia.