Through the repeated cycles of North Korean missile and nuclear testing, negotiations, and sanctions that have characterized international reaction to Pyongyang's proliferation, Japan has gradually lost ground it its effort to shape events on the Korean Peninsula. Tokyo made some progress in direct negotiations with Kim Jong-il, most notably the visits to Pyongyang by Prime Minister Koizumi Junichiro in 2002 and 2004, but with limited success in improving its strategic position. Since the succession of Kim Jong-un, Tokyo has put greater emphasis on ensuring it is prepared militarily for a more unpredictable North Korea, and strengthened its support for UN Security Council sanctions on North Korean proliferation.
On denuclearization, Tokyo has pursued its interests in collaboration with the United States, South Korea, and others in the region. The lack of direct leverage with Pyongyang continues to constrain Japan's ability to assert influence on negotiations. Whatever economic leverage Japan once had with the North has all but disappeared through the imposition of sanctions. Imports from North Korea were banned after the nuclear test in October 2006, and exports to North Korea were banned in June 2009 following the second nuclear test in May of that year. Restrictions on cash remittances by Koreans in Japan, an important source of revenue for Pyongyang, were also tightened following the missile test in April 2009. The only remaining source of potential leverage is the promise of economic reward should Pyongyang agree to denuclearize, but this too seems less effective in light of domestic Japanese sentiment on North Korean abductions of Japan's citizens.