Here is a thread regarding the Korean Conflict :-
Since time immemorial the Japanese have been ruthless warriors, a force that were reckoned with throughout history. The Korean empire and Chinese empire spent most of their time preparing themselves for Japanese invasions. (1/n)

Well the Japanese were never quite satisfied with their territory to say the least and had great geographical ambitious always.
( If you're wondering why are we discussing Japan instead of Korea, well that sums up the whole crisis, it's always been about the other nations) (2/n)

In around 1910, the Japanese officially annexed Korea bringing an almost end to the Korean dynasty, the Japanese empire went on to rule Korea till the end of WW2 where according to the peace treaty they had to give up land they had annexed (3/n)

Buckle up because this where the whole conflict begins to take shape.
So with the end of the second WW, two giant countries begin to form their own ideological blocs around the world( USA and USSR), a War that came to be known as the cold War. (4/n)

Both Germany and Korea are now divided into two parts North Korea and East Germany going to the Soviet Union and South Korea and West Germany going to the Americans and their western Allies.
For now I'll only focus on the Korean Division. (5/n)

So how does one go on to divide a full penensula of people into two administrations?
Well the Americans simply pick up a map and find latitude which devides the country into two (38th parallel). Shakalaka boom boom, the country is divided on the basis of a map. (6/n)

The Soviet union now wants Korea to be a communist regime, wheras the Americans want a capitalist society. A UN meeting is held and a time period is fixed for an election in korea and untill then both decide to station their troops in north and south of korea. (7/n)

Both the US and USR begin to withdraw their troops from the peninsula soon with shadow govts instilled in both theNorth(communist) andSouth(capitalist).But just when you think things began to cool down, the communist govt of the north with the help of a little trickstercalled 8/n

Joseph Stalin decides to invade the south to take control of the whole peninsula thus unleashing one of the first major wars of the cold War period. (9/n)

Story cut short, the war technically does not end but an armsticle is reached and a temporary border is setup at the 38th parellel which came to be know as the DMZ (demilitirized zone), sarcastically it is the most heavily militirized border on earth. 10/n

So Kim is technically the grandson of a communist puppet installed by the Soviets.
I'll cut to the chase here, the current scenario. So North Korea is probably the only country in the world which has nothing to do with the world, a mysterious little country who we have 11/n

idea about and it's functioning. So how does it survive in this globalised world and why is it a threat?

Well it's kinda simple, it basically survives off China. 12/n

china rounds up to almost 80% of N.K imports and takes about 84% of their exports. North Korea is basically China ka spoilt little brat who goes of showing off their nuclear capabilities scaring the shit out of South Korea, Japan and US (well probably the whole world). 13/n

US has a lot of troops stationed in the region, alot of their defense spending is accounted for in the region. Something that has frustrated Trump and has been constantly threatening to withdraw all his troops from the region. 14/n

Endnote:- There is a lot more into the crisis, for eg the rift between the alliance of Japan and SouthKorea, both are hardly Allies because of the horrendous past Japan bestowed upon them something that even the northfeels, yet US has always tried to maintain a balance (15/n)

China to has a imp role to play, the only reason NK has survived so long without destabilization is because China has let it happen,a dangerous North Korea is in the interst of the ChineseMoreover China can never let another hostile nation(india)have nuclear weapons at its doors

US who in the first place created this rift is now wants to move out of this mess, which is easier said than done honestly Anyone wondering why the US had to indulge in the first place well it's called the Truman Doctrine where US pledged to support nation influenced Communism16

Also technically because of no peace treaty between the two, North and South are still at War, a reason the North maybe uses to test their nuclear missiles every now and then All of this is just a small jist of whatever happened and why it happened, there are many more aspects.