In 1993, North Korea fired a Rodong medium-range ballistic missile into the Sea of Japan. After that, the world learned that the country might be developing nuclear weapons.
Then-U.S. President Bill Clinton drew up a plan to strike North Korea's nuclear and related facilities. During a summit with Japanese Prime Minister Morihiro Hosokawa, Clinton secretly asked for Tokyo's cooperation.
Japan refused a U.S. request to help with minesweeping operations, citing constitutional restrictions. Japan also disappointed the U.S. by saying there were limits to opening up commercial ports and airports to the U.S.