UN has issued a new sanction against North Korea. NK has accused USA of having nukes in SK aimed at them. In response to new sanction by UN north korea has threatened (or announced depending on news source) that it will "weaponise all plutonium". I sense WW3 may be nuclear.

I just want to say the thought that Iran or Korea, and their political actions, would spur a world war is ridiculous.
Not only is the global economy too important to risk destabilization over a petty dispute (Israel and Sth Korea are very small) but even if push came to shove the Western nations would be completely over powered by the triple whammy of China, Russia and to a lesser degree much of Africa (China's economic influence, ie. Sudan, should not be underestimated).

i think you are right they will fight for resources.

Damn you! I wanted to say that!

It's unlikely that Korea or Iran has the leverage to start a global war.

Even if either decided to start throwing nukes, it wouldn't start a global war. No one would back those regimes, and they would be pounded into dust within days or even hours if there was a nuclear strike. Who's gonna get NK's back? The Chinese? Unlikely. China would risk economic meltdown, and for what purpose?

The only way a world war will happen is if two or more major entities begin to fight amongst eachother:

China
US
Russia
EU
India

Otherwise, it will only be a localized conflict. I don't know if we'll fight another world war, but I feel that whatever is fought may be more economic than militaristic.

One of the great things about capitalism is that people would rather sell things to each other than fight, and that's coming from a socialist.

Also, it is very difficult for democracies to fight each other (the only one I can think of is the American Civil War, and its a stretch calling the South a democracy with less than 20% of the population being able to vote).  With the world as democratic as it is right now, I have a hard time seeing another World War unless a lot of social change happens.

I would imagine that the unification of Europe would cause a power shift so big that I imagine it would pi$$ a lot of nations off.

Iran and Korea don't have any real power and no-one would back them.

Do you think that'll really happen? With the current state of the EU and tensions already? (although if you're talking about during wartime/impending war time, I don't know what to think).

They don't, but the major powers are always looking for ways to leverage smaller crises to their gain. North Korea begins to mobilize, and Russia sees an opportunity to leverage more control in the Far East. Iran mobilizes against Israel, and China sees an opportunity to secure immense oil resources to their own gain.

World War I started for similar reasons. World War II was different, in that it was almost inevitable, the question being exactly who would fight whom (there was as much a chance of the Germans allying to the Soviets as fighting against them, and the racist Germans had ideological grounds to fight against the Italians and the Japanese)

China
US
Russia
EU
India

if those are the players butting heads in a true world war its over in a hour.