For the matter, why have we let NK get so far, shouldn't something have been done earlier under Bush Jr.? — Question

Like what?

I'll let you figure that out. X-)

Nobody knew healthcare foreign policy could be so complicated

We have some really bright minds on our side.

Here's what I think. The US never considered NK a threat, in the past, present, or future. We will always have an absolute advantage of whatever technology they copy from the Russians or Chinese. Which means that despite our assurances of honoring past agreements with South Korea and Japan, we do not take their safety in as high an esteem as ours (US').

Now call me a liar.

...to the dismay of China and Russia — Question

I wouldn't be too sure about that. It would be incredibly ignorant of you to assume their lack of influence in existing and potential proxy wars along with the US. It is economics and, indeed, SK and Japan were the primary impetus behind the deterrence of war, but it is not safety that the US esteem above all else. It is profiteering.

That's understandable. I never assumed the US was even capable of defending both Japan and let alone South Korea against someone like China and Russia.

As for Russia and China, there's no doubt in my mind that they stalled any peace agreements and UN resolutions against NK along with, I think - without a doubt - helping NK acquire technology and expertise to assemble a nuclear bomb and make the uranium fuel.

It might be that NK was always a bargaining chip over diplomatic issues between the three powers. Now, it seems things have grown out of control.

Yes, America-above all- exports capitalism, in many forms.

The US nudges China to start dealing with it. China will start dealing with it.

War seems on the horizon — Question

How so?

What is so different now from earlier times?

That the US has Trump? Nah.

If the cease-fire has held since the 1950's, a part a few incidents, what is now so different?

1990s

March 1990: The fourth North Korean infiltration tunnel is discovered, in what may be a total of seventeen tunnels in all.
May 1992: Three Northern soldiers in South Korean uniforms are killed at Cheorwon, Gangwon-do; three South Korean soldiers are wounded.
December 17, 1994: A US Army OH-58A+ Kiowa helicopter crosses 10 km into North Korean territory and is shot down. Of the crew of two, one dies and the other is held for 13 days.[22][23]
May 1995: North Korean forces fire on a South Korean fishing boat, killing three.
October 1995: Two armed North Koreans are discovered at the Imjin River; one is killed.
April 1996: Several hundred armed North Korean troops enter the Demilitarized Zone at the Joint Security Area and elsewhere on three occasions, in violation of the Korean armistice agreement.
May 1996: Seven Northern soldiers cross the Demilitarized Zone, but withdraw after warning shots are fired.
May & June 1996: North Korean vessels twice cross the Northern Limit Line and have a several-hour standoff with the South Korean navy.
April 1997: Five North Korean soldiers cross the Demilitarized Zone in Cheolwon, Gangwon-do, and fire on South Korean positions.
June 1997: Three North Korean vessels cross the Northern Limit Line and attack South Korean vessels two miles (3 km) south of the line. On land, fourteen North Korean soldiers cross 70 m south of the center of the DMZ, leading to a 23-minute exchange of fire.[24]
July 1998: A dead North Korean frogman was found with paraphernalia on a beach south of the DMZ.
June 1999: The First Battle of Yeonpyeong, a series of clashes between North and South Korean vessels, takes place in the Yellow Sea near the Northern Limit Line.

2000s

October 26, 2000: Two US aircraft observing a ROK army military exercise accidentally cross over the DMZ.[22]
2001: On twelve separate occasions, North Korean vessels cross the Northern Limit Line and then withdraw.
November 27, 2001: North and South Korean forces exchange fire without injuries.
June 29, 2002: The second battle of Yeonpyeong leads to the deaths of six South Korean sailors and the sinking of a South Korean vessel. The number of North Koreans killed is unknown.
November 16, 2002: South Korean forces fire warning shots on a Northern boat crossing the Northern Limit Line. The boat withdraws. The similar incident is repeated on November 20.
February 19, 2003: A North Korean fighter plane crosses seven miles (11 km) south of the Northern Limit Line, and returns north after being intercepted by six South Korean planes.
March 2, 2003: Four North Korean fighter jets intercept a US reconnaissance plane over the Sea of Japan.
July 17, 2003: North and South Korean forces exchange fire at the DMZ around 6 AM. The South Korean army reports four rounds fired from the North and seventeen from the South. No injuries are reported.[25]
November 1, 2004: North Korean vessels, claiming to be in pursuit of illegal fishing craft, cross the Northern Limit Line and are fired upon by the South. The vessels withdraw 3 hours later.
May 26, 2006: Two North Korean soldiers enter the DMZ and cross into South Korea. They return after South Korean soldiers fire warning shots.
July 30, 2006: Several rounds are exchanged near a South Korean post in Yanggu, Gangwon.

Wikinews has related news: Korean navies exchange fire
October 7, 2006: South Korean soldiers fire warning shots after five North Korean soldiers cross briefly onto their side of the border.
October 27, 2009: A South Korean pig farmer, who was wanted for assault, cut a hole in the DMZ fence and defected to North Korea.[26]
November 10, 2009: Naval vessels from the two Koreas exchanged fire in the area of the NLL, reportedly causing serious damage to a North Korean patrol ship.[27][28] For more details of this incident, see Battle of Daecheong.

2010s

January 27, 2010: North Korea fires artillery shells into the water near Baengnyeong Island and South Korean vessels return fire.[29][30] Three days later, North Korea continued to fire artillery towards the area.[31]
March 26, 2010: A South Korean naval vessel, the ROKS Cheonan, was allegedly sunk by a North Korean torpedo near Baengnyeong Island in the Yellow Sea. A rescue operation recovered 58 survivors but 46 sailors were killed. On May 20, 2010, a South Korean led international investigation group concluded that the sinking of the warship was in fact the result of a North Korean torpedo attack.[32][33] North Korea denied involvement.[34] The United Nations Security Council made a Presidential Statement condemning the attack but without identifying the attacker.[35]
October 29, 2010: Two shots are fired from North Korea toward a South Korean post near Hwacheon and South Korean troops fire three shots in return.[36]
November 23, 2010: North Korea fired artillery at South Korea's Greater Yeonpyeong island in the Yellow Sea and South Korea returned fire. Two South Korean marines and two South Korean civilians were killed, six were seriously wounded, and ten were treated for minor injuries. About seventy South Korean houses were destroyed.[37][38][39] North Korean casualties were unknown, but Lee Hong-gi, the Director of Operations of the South Korean Joint Chiefs of Staff (JCS), claimed that as a result of the South Korean retaliation "there may be a considerable number of North Korean casualties".[40]
October 6, 2012: An 18-year-old North Korean Army private defects to South Korea. He is apparently not detected as he crossed the DMZ and has to knock on an ROK barracks door to draw attention to himself. The soldier later tells investigators that he defected after killing two of his superiors.[41][42]
September 16, 2013: A 47-year-old man is shot dead by South Korean soldiers while trying to swim across the Tanpocheon Stream near Paju to North Korea.[43]
February 26, 2014: South Korean defense officials claim that despite warnings a North Korean warship has repeatedly crossed into South Korean waters overnight.[44]
March 24, 2014: A North Korean drone is found crashed near Paju. The onboard cameras contain pictures of the Blue House and military installations near the DMZ. Another North Korean drone crashes on Baengnyeongdo on March 31.[45][46]
October 10, 2014: North Korean forces fire anti-aircraft rounds at propaganda balloons launched from Paju. South Korean military return fire after a warning.[47]
October 19, 2014: A group of North Korean soldiers approach the South Korean border and South Korean soldiers fire warning shots. The North Korean soldiers return fire before retreating. No injuries or property damage result.[48]
June 15, 2015: A teenaged North Korean soldier walks across the DMZ and defects at a South Korean guard post in north-eastern Hwacheon.[49]
August 4, 2015: Two South Korean soldiers were wounded after stepping on landmines that had allegedly been laid on the southern side of the DMZ by North Korean forces next to a ROK guard post.[50] Kim Jin Moon of the South Korean-based Korea Institute for Defense Analyses, suggested that the incident was planned by members of the General Bureau of Reconnaissance to prove their loyalty to Kim Jong-un.[51]
August 20, 2015: As a reaction to the August 4 landmines, South Korea resumed playing propaganda on loudspeakers near the border.[52] In 2004 both sides had agreed to end their loudspeaker broadcasts at each other.[53] North Korea threatened to attack those loudspeakers, and on August 20 North Korea fired a rocket and shells across the border into Yeoncheon County. South Korea responded by firing artillery shells back at the origin of the rocket. There were no reports of injuries on either side.[52][54] Following threats of war from the North, and various troops movements by both North and South Korea and the United States, an agreement was reached on August 24 that North Korea would express sympathy for the landmine incident in return for South Korea deactivating the loudspeakers.[55]
January 3, 2016: South Korean soldiers fired warning shots at a suspected North Korean drone near the DMZ.[56]

(Source, wikipedia)

Well, my only worry is that when do the NK's really want to strike us? I mean, they're been dreaming about it for a while now already.

What would North Korea gain from using nukes offensively? They want to unify the Koreas, not blow them up...

They're also well aware that if they actually attacked anyone else with nukes every other nuclear armed country in the world would probably take the opportunity to test their submarine based nuke delivery systems (on North Korea).

Maybe we had a window to invade between the collapse of the Soviet Union and 2003, when NK supposedly developed usable nukes, but the ensuing war would have caused millions of North Koreans to die and possibly millions of South Koreans too as every weapon of mass destruction becomes a viable tactic to a collapsing government intent on keeping power by any means necessary.

Nope... We would rather just wait for it to economically collapse just like the soviet union did. Since it managed to get nukes we're pretty much forbidden from ever invading it, hence the cold war like atmosphere which presently engulfs North Korea.

I don't really know what the insular North Korean regime wants. I am certain that the collapse of the Soviet Union provided no window of opportunity because China would almost certainly have countered any invasion.

I also don't know what it will take for them to collapse economically. They have never been a robust economy to start with, and they have endured famine.

The problem is that post atomic era, war has become obsolete, which North Korea is finding it hard to accept. How far are they willing to go is the elephant in the room.

The US never considered NK a threat, in the past, present, or future. We will always have an absolute advantage of whatever technology they copy from the Russians or Chinese. — Question

Are you sure they are copying technology? Their missile development is pretty slow and steady for working from specs. They probably did get some basics from either China or the Soviet Union on nuclear technology, but again, the rate of development doesn't seem to be that rapid.

Is NK a threat? Well, sure they are. If they can miniaturize a reasonable-sized nuclear weapon so that it would fit on top of a reasonably powerful missile (intercontinental or not), and since they already have submarines that can launch a missile, and even if they can land one bomb successfully in the US, say on Washington, D. C., or Los Angeles, I think we would rather seriously resent having that happen.

Of course, we do have absolute superiority over NK, but NK is very, very close to Russia and the PRC. My guess is that both Russia and China would rather seriously resent us having bombed to smithereens a country on their borders. I don't think SK or Japan would be thrilled about it either.

The problem is that post atomic era, war has become obsolete — Question

Hardly. Regional wars have been going on continuously since the beginning of the atomic era. It isn't obsolescence that has prevented nuclear war from happening, it's mutually assured destruction.

For the matter, why have we let NK get so far, shouldn't something have been done earlier under Bush Jr.? — Question

Like what? North Korea isn't an island nation a thousand miles from anyone else; it butts up against China and Russia, is across the DMZ from Seoul, (which is far larger than New York and LA, combined) and is across the small sea of Japan. In other words, it's an international china shop that bulls can not operate in without causing a lot of wreckage.

My guess is that China will follow its own self interest, and take some form of 'guardianship' over its ally, NK. NK was historically a vassal of China.

I don't really know what the insular North Korean regime wants. I am certain that the collapse of the Soviet Union provided no window of opportunity because China would almost certainly have countered any invasion.

I also don't know what it will take for them to collapse economically. They have never been a robust economy to start with, and they have endured famine. — Bitter Crank

I know that China has used them for quite some time as an easily exploitable trading partner. Really China is probably the reason why they've been able to make it through extended famine(s) (smuggling gold out of NK is one example). The main weakness of their economy is that A, nobody is permitted to trade with them (China still does it outside of the humanitarian trades knowing it's too economically powerful to be severely sanctioned and they get away with some plausible deniability AFAIK), and B, most of their money seems to get spent directly on the military and their apparatus' of internal political control (preventing growth).

Perhaps china would have been strong enough in the early nineties to prop NK against American backed invasion (I hadn't considered China), but maybe not. We still would have had to face ridiculous casualty rates from the chemical warfare which surely would have been employed.

Side note: I'm sure from China's perspective, they would love for North Korea to grow economically so it could have a trading partner/ally in the region not beholden to western political influence.

Are you sure they are copying technology? Their missile development is pretty slow and steady for working from specs. They probably did get some basics from either China or the Soviet Union on nuclear technology, but again, the rate of development doesn't seem to be that rapid. — Bitter Crank

Well, you know, they have the GDP of some banana republic. There's only so much you can do with that much money to go around. Iran has only made so much progress due to having vast oil reserves? What does North Korea export? Counterfeit US currency (and probably European too), heroin, methamphetamine, and arms to rogue nations. Certainly the A.Q. Khan nuclear smuggling network helped them get to where they are; but, a certain amount of expertise is required to build centrifuges for uranium enrichment along with weapons design. Where do you get the brains to assist in building those? Most likely China helped with the scientific team needed to assemble said weapons and fuel. Soviet technology also proliferated considerably after the collapse. The technology is there, you just need human capital (scientists) and money to get the job done.

Is NK a threat? Well, sure they are. If they can miniaturize a reasonable-sized nuclear weapon so that it would fit on top of a reasonably powerful missile (intercontinental or not), and since they already have submarines that can launch a missile, and even if they can land one bomb successfully in the US, say on Washington, D. C., or Los Angeles, I think we would rather seriously resent having that happen. — Bitter Crank

I talked about this with a friend, and the consensus is that North Korea would need to build technology that is far beyond their capabilities to evade sonar detection to get close enough to our coasts to launch and strike a target successfully. They are FAR away from that ever happening, and Russia and China aren't crazy enough to give a modern stealth sub to North Korea just so that they can have their wet dream of starting another World War. I don't know the technicalities as this is some pretty top secret shit; but, I'm assuming stealth is still beating detection methods.

Of course, we do have absolute superiority over NK, but NK is very, very close to Russia and the PRC. My guess is that both Russia and China would rather seriously resent us having bombed to smithereens a country on their borders. I don't think SK or Japan would be thrilled about it either. — Bitter Crank

Well, the problem is the concentration of power in North Korea. Whereas the Soviets were in many regards totalitarian, there was some level of check and balances to be maintained within the regime. North Korea presents a problem with the unconditional support of one man, and thus a great chance for irrationality to go too far in saber rattling.

Hardly. Regional wars have been going on continuously since the beginning of the atomic era. It isn't obsolescence that has prevented nuclear war from happening, it's mutually assured destruction. — Bitter Crank

MAD no longer applies nowadays, not to the degree it did in the past with the balance of power between us and the Soviets. We have superiority in almost every regard. That's not to say that we wouldn't suffer casualties, just that any losses an enemy would incur would far outweigh our losses.

With North Korea, you just have them trying to increase their regional influence with threats against peaceful nations like Japan and to a lesser extent South Korea. The sad thing is that Japan, which is one of the most technologically advanced country in the world has been prevented from developing anti-ICBM technology, which has always been inferior to delivery technology. I suspect, as the US usually does, we import the brightest minds from Japan and have them work for us and then sell them back their work to Japan.

We dissallow Japan from having a standing army capable of invading another nation (or at least used to, do we still?) because of that whole deal from the 40's. Similarly, we disallow them nukes (we disallow nukes for anyone who doesn't already have any). I'm not entirely sure about the legality of developing anti ICBM technology, but if you're a nuclear armed nation and someone gives the ultimate ICBM countermeasures to your nuclear armed enemies, you're fucked. (but with the numbers of ICBM's available, combined with traditional bombers and nuclear armed subs, MAD is probably more guaranteed than ever before)

If we're talking about military technology though, Japan ain't the prodigy. The western military industrial complex as a whole has a firm grip on the ultimate weapons of today, with the U.S being it's main consumer.

(but with the numbers of ICBM's available, combined with traditional bombers and nuclear armed subs, MAD is probably more guaranteed than ever before) — VagabondSpectre

Not really, because there's nobody to assure destruction with. Possibly, if China and Russia ganged up together and came up with the bright idea of attacking us, then? Maybe. But, then there's France, Israel, UK, India, Pakistan (?), that would assist with the total annihilation of the known world. A desirable outcome for China and Russia, not at all. North Korea's wet dream? Yeah, for sure.

EDIT: You know a nation that has gone through famine and such poverty really doesn't see nuclear war as that bad a thing if you think about it.

North Korea might be bat shit crazy as a nation, but they still must have sane military and economic strategists. They can barely stay afloat while in a perpetual 1984 state of faux war. A real war would likely exhaust them very rapidly.

If North Korea actually nuked someone then everyone else, including China and Russia, would lay waste to every strategic target inside of North Korea with nuclear attacks of their own, or they would at least stand by and bow their heads (China and Russia that is).

That said, North Korea cannot ensure the destruction of anyone but SK and themselves so far as I'm aware, and so only SK is really included in the "mutual destruction" resulting from NK aggression.

but, a certain amount of expertise is required to build centrifuges for uranium enrichment along with weapons design. — Question

I'm a little fuzzy about this... plutonium is produced in a uranium reactor, right? then the plutonium is chemically separated from the uranium--correct? It's U235 that is separated from U238 by gaseous centrifuges, true?

Plutonium is made in breeder reactors. Its a man made element last I recall. What's needed before that step is enriched uranium as far as I know. But you can have bombs made out of enriched uranium only. Just that theyre not as easy to miniaturize.

There are different methods of extracting the weapons grade plutonium from the breeder fuel. I think the most modern method is to use lasers as in some resonance exciting of gases to separate isotopes at certain frequencies. This is ultramodern and efficient as well as very dangerous due to ease of concealment. I don't think you can use centrifuges without giving away your hiding spot due to extremely sensitive satellite radioactive detectors.

https://en.m.wikipedia.org/wiki/Isotope_separation

How will Trump proceed? — Question

Nobody - not one single person - knows what Trump will say next, let alone do. Hopefully the adults are in charge of this issue, if not, god help us all.

Well, my only worry is that when do the NK's really want to strike us? I mean, they're been dreaming about it for a while now already. — Question

First and foremost: it doesn't want to do that.

What the rulers of North Korea want is simple: to remain in power. And in order to do so, they need the threat of an impending war with the US. That justifies the militarization of the whole country and why the military comes first in everything, the Songun policy.

As to the North Korean nuclear bomb, it is a rational and totally logical decision for a militarized country where the whole existence of the system and it's leadership depends on the army and the "threat" imposed by it's southern neighbour and the US.

North Korea simply cannot match in any way the sheer economic power of the First World country like South Korea. Hence it cannot compete with conventional forces, especially in air power, with the Republic of Korea and it's ally the US. And so the nuclear deterrent is far cheaper than to try to create a conventional force that could deter "US aggression". The next fact is that nuclear weapons are a great deterrent against any kind of "pre-emptive attack". This can be seen as how aggressive the US has been towards Iran compared to North Korea.

And let's face it. As I said, the primary goal of the ruling family is to stay in power. And if only some time ago there was widespread famine in the country, the truth is that without the army the ruling family wouldn't be in power. Hence for Kim Jong Un (and his father & grandfather) the real base of power and the real people that they have to please are the people in the armed forces. And at some level in those in the armed forces have to look at the prospect of war in real terms, what their true capabilities are against the true ROK & US forces. Then nuclear weapons is the only logical answer for the regime to be credible in the eyes of those most important to it: the North Korean soldiers and officers.

It seems to me that there is no doubt in my mind that NK has acquired technology from external sources as to how to build an ICBM that can carry a nuke.

If anything, that's an issue that has to be addressed.

What does Kim Jung Un want? Does he want to start WWIII and have his nation and rule destroyed in the process? Or does he think that the world will fold? If so, what does he get from it? Does he seriously believe he's going to extend his rule over South Korea? What kind of 'victory' is he imagining?

What does Kim Jung Un want? — Wayfarer

From what I gather, to maintain power and survival of his regime. The US is the devil incarnate for North Koreans. So, any rhetoric in regards to the US will always be in the form of vitriol and hatred.