China is the far bigger player in NK.

It will be interesting to see how China reacts to the korean peace-talks.

If SK and NK become one country, a few decades from now, SK won't be willing to give up things like free media and free elections. That means, a unified Korea will also have those and will be a natural ally of the US.

That means instead of poor violent troublemaker North-Korea, China will now have a democratic, free Korea on its southern border.
And Russia will also not like that at all, because Korea shares a tiny border with Russia and then Russia would have a US-allied country directly on the border. Avoiding such a scenario is why Russia went to such great lengths to prevent Ukraine from joining the West.

reason why Russia went to great lengths to prevent Ukraine from joining the West I believe is because of the food produced from the Ukraine.

The only way I see the negotiations would be viable is for a continued U.S. presence in the region, and it will be interesting if NK would accept that

South Korean, DPRK leaders promise to meet more often after ongoing summit

http://en.people.cn/n3/2018/0427/c90000-9454415.html

It's not about Ukraine's food. Russia's geopolitical strategy is to surround itself geographically with vassal-states, as a buffer to other power-blocs. When Yanukovych was overthrown, that meant that the West had arrived at Russia's border and Russia cannot allow that to happen. That's why they support the separatists: Russia wants a new east-ukranian state as a buffer between itself and West-Ukraine.

A peace treaty plays right into what China and Russia want. It puts the USA in the awful situation of "so, why are your troops and bases there when there is not threat of war?" Then we look like the aggressor.

Conversely, getting rid of the nukes, gets rid of the sanctions.....and with no sanctions, and we still have bases in SK....whats to stop NK inviting China, Russia or both to set up shop? When Russia intervened in Syria, they telegraphed to the world they were back in business and if they have a base on your territory and should a popular uprising occur, they got your back. And as paranoid Kim is, this is probably very attractive to him.