While I would generally say yes, at the moment things are a little less certain. Having worked here for about 18 months, I have come to know the country quite well. The people are normally very polite and sometimes quite generous. Crime seems to be lower than any country I have ever visited before and CCTV across the country means that most crimes are deterred.
This is all combined with compulsory fingerprinting and ID cards, which are required and need to be up to date for most parts of daily life. For example, you can not open an account, get a SIM card or phone, or even rent a place without having an up to date ID card.
This works well and has created a very safe country. However, personally I feel that it is safe to travel South Korea more because of the culture, than the laws and their enforcement. The people think more about the group and the country, than themselves individually. This creates quite a unique feel.
All that said, at the moment North Korea has made nuclear threats against the South and the USA. They have also reportedly revoked the cease fire agreement. While this is concerning, there is great pressure against them proceeding with any attack and they know that much of the world would be against them over this. Hence, although there are threats, I personally don not feel -In danger- just yet. Hopefully this will all be resolved soon and it will be safe to travel South Korea without these concerns. For the mean time, please check with embassies before making travel plans.