<h1>South Korea to boost defense spending and arms purchases, prompting review of U.S. alliance obligations and agreements</h1> South Korea's president announced plans to increase defence spending and acquire advanced weapons to build a more self-reliant military amid concerns about the U.S. security commitment under the current U.S. administration. The move raises legal and treaty implications for the U.S.-ROK alliance, including potential renegotiation of cost-sharing for U.S. forces, adjustments to the U.S. troop presence, and the planned transfer of wartime operational control to a binational command led by South Korea. Changes could affect obligations under mutual defence arrangements, deterrence under the U.S. nuclear umbrella, and procurement and industrial policy for the domestic defence sector.