Yeah, the reason why I fear this over the Ukrainian conflict is the fact that Kim Jong Un can be very unpredictable. He made various statements claiming to destroy the USA and South Korea, but he never went through with it.
We are seeing a real mobilization of troops by North Korea, which can either be a huge bluff or a real attack.
I have 3 scenerios that can happen as a result of this.
Let's just start with the most extreme outcome.
In this scenario, North Korea is actually attacking South Korea, and Kim Jong Un plans to invade the whole of South Korea.
The UN tries to warn Kim Jong Un, but he simply ignores everybody, believing that any resolution against North Korea would be vetoed by Russia and China.
Most of the NATO members begin to send arms to South Korea in to support South Korea. China and Russia remain neutral, in fear of escalating the conflict.
North Korea decides to launch a nuclear missle at South Korea. This sends 3 messages to the world.
1. "We were able to create a nuclear weapon and the USA didn't notice it"
2. "We have the capability to launch nuclear weapons, so you must respect us as a nuclear power."
3. "If no action is taken against this crime, there is no reason to prevent the use of nuclear weapons in combat. If any action is taken, I will retaliate."
Kim Jong Un demands to take over South Korea. Park Geun-hye gives in to the demand, because he fears escalation of the conflict.
Since the entire world is shaken up by this event, Obama and Putin decide to put aside their differences and they prepare a secret invasion of North Korea. They both realize that it would just be a matter of time before Kim Jong Un would make another demand.
The USA and Russia invade North Korea, and while this is happening, Kim Jong Un decided to drop a nuclear bomb on Moscow. This activates Russia's Black Hand retaliation system. The remaining humans will have to live without any modern utilities. It would just be a matter of time before the ammunition for the rifles runs out, and humanity will be back in the stone age. Because we have stripped the Earth of her resources, the humans will no longer be able to make scientific progress.
Many of the new religions will refer to this as some sort of rightious act by the Deity/Deities. The Homo Sapien species has wasted its chance at Galactical Dominance. If we were the only intelligent species in the universe, we would have commited the greatest sin of all.
With the depressing scenario out of the way, let's focus on a more optimistic scenario.
In this scenerario, Kim Jong Un is just interested in the northern part of South Korea. He is especially interested in taking Seoul, to show the world that Kim Jong Un can take the capital of South Korea.
ISIS decides to launch an offensive against Israel. Obama decides to send reinforcements to The Middle East. This causes the USA to put South Korea lower on their priority list. Kim Jong Un explains that he is just interested in taking the northern parts of South Korea, and he has no interests in attacking any NATO member.
A few years later, in the USA, more and more jobs are being replaced by robots. This causes massive outrages of the majority of the workforce.
Russia decides to continue the offensive against Ukraine, seeing as how the USA is in an internal conflict and they still haven't pulled their troops out of Israel and South Korea.
North Korea is launching a new offensive against South Korea, with the intent of taking down the entire country. ISIS realizes that they can let America crumble slowly if they are faced with multiple conflicts at once (Ukraine, North Korea and their internal conflicts).
The American troops are being pushed back in Israel and South Korea. This causes most of the European countries to lose trust in the USA.
I don't think that this would result in a second Cold War, but it could be a possibility.
In this scenario, Kim Jong Un reveals that "it was just a prank bro!".
Everybody lives happily ever after.
Kittens and rainbows.
The end.