Following North Korea's successful nuclear test, South Korean politicians are openly mooting the idea of acquiring their own nuclear deterrent, according to a report in the Korea Times.
One such politican, Won Yoo-chul, suggested that the country develop nuclear weapons on the condition "that we immediately scrap them if the North gives up its nuclear program." Another conservative lawmaker described the current state of South Korean defenses as trying to defend your home with a pebble against a gangster with a machine gun.
Other lawmakers prefer to remain under the U.S. nuclear umbrella (the U.S. stopped basing nuclear weapons in Korea in 1991 as efforts to "denuclearize" the Korean Peninsula began). And there are several legal obstacles in front of South Korea: they would have to pull out of the Non Proliferation Treaty and a bilateral nuclear accord with the U.S. before it could obtain nuclear weapons.
Still, one can see the logic of South Korea's nuclear threats: they may just be enough to goad China into taking a tougher line against Pyongyong.