The U.S. Supreme Court’s decision striking down Washington’s tariff scheme has emerged as a new variable affecting security negotiations between Seoul and Washington, raising concerns that uncertainties surrounding the tariff issue may hinder defense cooperation. Officials here have said the trade issue is separate from security issues, including Seoul’s pursuit of nuclear-powered submarines and expanded rights over uranium enrichment and spent fuel reprocessing. However, the security negotiations have already been delayed by the deadlock in tariff talks in recent months, especially after U.S. President Donald Trump on Jan. 27 threatened to raise levies on Korean goods, citing Korea's slow progress on pledged investments. The timing of a planned visit by a U.S. interagency delegation is now being closely watched. Seoul expects officials from the White House, the State Department, the Department of Defense and the Department of Energy to participate in the security negotiations, saying earlier this month that the delegation may arrive at the end of February or early March. However,