"US and South Korea strengthen nuclear defense against North Korea"

The US and South Korea have reached a landmark agreement to counter the North Korean nuclear threat. The Washington Declaration will involve the periodic deployment of US nuclear-armed submarines to South Korea and involve Seoul in US nuclear planning operations. In return, South Korea has agreed not to develop its own nuclear weapons. The new agreement will strengthen the allies' cooperation in deterring a North Korean attack. The US already has a treaty obligation to defend South Korea and has previously pledged to use nuclear weapons if necessary.