There is no South Korean nuclear program. It is North Korea which has an illegal nuclear program.
"We have more" & "Ours are bigger", strategies.
China would prefer a nuclear-weapon-free Korean peninsula. However, China is North Korea's foremost foreign ally, so it is often unwilling to join the US and other nations in boycotting or sanctioning North Korean unwillingness to forego nuclear weapons.
The US is strongly opposed to the North Korean nuclear weapons program and has been trying very hard to discourage North Korea from building nuclear weapons, although as we have seen, North Korea is building them anyway, in defiance of all forms of international pressure from the US or the UN.
Not during the Korean war...
They won’t give up the nuclear program and this is because they see it as a means to power and recognition in the world. In looking at the situation I think that China has a big hand into the problem. North Korea can’t keep the lights on in the country, so they have to be getting money and support from China or another country.
The North Korean nuclear program began under Kim Jong-Il when he took power in the 1990s; this caused international sanctions against him, which cut aid. This along with lack of Soviet support and economic mismanagement created a famine that starved thousands. The height of North Korea's economy began in the 1960s and came to a close after the death of Kim Il-Sung in 1994. During this time there were no sanctions against them, because there was not a nuclear program. Using the theory of associations, Kim Jong-Il's nuclear program crippled the economy.
in the related links box below I posted the official article regarding US policy against North Korea.
They don't have one yet. However they try so they can threaten others.
In North Korea and China during the Korean war. He got fired by Truman for that.
During President Clinton's term, international inspectors were not allowed to look at North Korean sites where nuclear waste was being dumped because the North Koreans did not want people to know what was going on. That country continues to keep much of their nuclear capability a secret from the rest of the world.
It would have a null effect. Currently, the US Navy and US submarines are deployed around the Korean Peninsula and the Japanese archipelago. There are nuclear missiles within range of hitting North Korea. Any deterrence that having nuclear weapon on Japanese or Korean soil would have is the same as what is already being achieved.