THE United States plan to banish its tactical nuclear weapons worldwide may be handing North Korea both a military advantage and a political defeat.The Communist-run regime in the north has long contended that the US deploys nuclear weapons in South Korea. But the North has also insisted upon their removal before it would accept any international inspection of its nuclear facilities, which the US believes will be able to produce a nuclear bomb by the mid-1990s. President Bush, in making his surprise announcement, has in effect called the north's bluff. Withdrawal of any alleged US nuclear weapons will now add pressure on the north to open up to inspection. Pyongyang signed the Nuclear Non-Proliferation Treaty in 1985, but refuses to sign the related accord on outside scrutiny of nuclear plants. "This announcement will deprive North Korea of any pretext to delay signing the safeguards," said Taizo Watanabe, a Japanese government spokesman. A second possible spinoff of the US plan would be to push along peace talks between North and South Korea. Those talks, which began in 1990, have stalled on the condition of a possible security pact between the two nations. Without such a pact, the Korean peninsula could remain a stubborn remnant of a military standoff from the cold war, and a potential nuclear flashpoint. South Korean President Roh Tae Woo ordered his Cabinet Oct. 1 to draft a "joint arms-reduction plan" to be proposed to the north at the next round of prime ministerial talks, which are slated for Oct. 22-24. The plan would include "confidence-building" measures, such as mutual notification of troop exercises and other military information. "North Korea may surprise us all and agree to most of the south's proposed draft for a security treaty," said Kim Kyung Won, the former South Korean ambassador to the US and now president of a Seoul think tank, the Institute of Social Sciences. The north recently submitted to one of the south's demands and agreed to join the United Nations under a separate membership last month. In recent months, a number of American and South Korean scholars have suggested that the US declare that it had no land-based nuclear weapons in the South, since such weapons are considered by many no longer to be necessary. US officials will only say that many US weapons systems in South Korea are "nuclear capable." North Korea at first welcomed the Bush plan, saying it will "open the way" for it to sign the safeguard accord. But a new obstacle was imposed in a statement by a ranking North Korean official carried Sept. 29 by the official North Korean Central News Agency. The official, Kim Yong Sun, said the US should guarantee never to use any nuclear weapons against North Korea, "so that we may sign the nuclear safeguards accord, instead of only forcing a unilateral inspection of our country." Even after withdrawing tactical weapons, the US keeps strategic weapons on submarines or in land-based silos. "Can the US really promise not to use ICBMs against North Korea?" asked a South Korean policymaker. "That's ridiculous." He added that the new North Korean demand would soon be seen as frivolous. The US, along with South Korea and Japan, has tried to prevent aid to North Korea until it agrees to the inspection accord. With its economy in shambles because of the withdrawal of Soviet aid, the regime of Stalinist leader Kim Il Sung is under pressure to allow the nuclear inspections in order to win trade and aid from the West and Japan. "To thwart nuclear weapons development in North Korea has become an urgent task, not only for us, but also for the entire community of nations," President Roh said. Just before the Bush announcement, South Korean Defense Minister Lee Jong Koo was quoted in a legislative hearing as warning of possible military action against the north's facilities if its nuclear program is not halted. He stated that North Korea will be able by 1993 to produce 50 kilograms of plutonium a year, enough for six to seven bombs of the power of those dropped on Hiroshima. He also said South Korea should remain under the US "nuclear umbrella." "We oppose any proposal to remove the nuclear umbrella," said Minister Lee. "I think the assertion that only the Korea peninsula should be a nuclear-free zone is unrealistic and meaningless."