Look at the state of the nations who consistently oppose the United States. For one, it is a very small list. Two, they are almost always isolated from the global community (Cuba*, Iran*, N. Korea, etc.). This isolation leads to the fact that their economies are not the greatest. Three, look at what happens when they repair relationships with the US. China is the single greatest example of this when it pulled back much of its soviet style policies and reestablished trade with the US. China went from being a backyard, impoverished, farmstead to one of the leading global economies in the world. Cuba and Iran have already had massive economic growth simply by the prospect of normalizing relations. In this continually interconnected world where the US has almost complete hegemony, fight it is stupid.
Kim junk-Un is the most swaggiest dictator in the world!!!!! Look at the movie The interview! He has a little fat boy at the corner oft the street right next to the plastic grocery store!!!! He gave dave skylark a puppy and the tried to kill it! And he even let him ride a tank will drinking margaritas and listening to Katy Perry! (lol dis was a joke)
Sure, DPRK would like to wipe the US off of the map. But think about if North Korea and the US. North Korea would have ties with them and not go against every single thing the UN or what have you suggest, otherwise compromising their relationship. Also, it would prevent DPRK from going to war with the US and it's allies (which pretty much consists of over half of all the countries in existence), effectively setting grounds for piece. It would even go to war in the first place, both sides knowing that it might escalate to nuclear heights, which nobody wants because of MAD. All in all, if DPRK was allied with the US, there would be more peace within the rest of the world, and we buy ourselves time before the next time somebody launches a nuke.
North Korea absolutely hates us. If we bothered to waste our time to offer a peace treaty to them, they would nuke us right then. North Korea has anti-America policy blasted every day in North Korea, the common folk hate us too, thinking that we are an imminent danger, threatening to attack for no reason.
North Korea is run by a family of dictators that would very much like to wipe the United States off the map. To be honest I'm not even sure why this question is being asked. There's no reason to ally with them. Our technology is superior to theirs, and if they ever foolishly decide to officially declare war on us, well...It's Kim Jong Un's funeral.