About a decade ago, I lived in SK for 3 years. Taught at a couple of universities. And I've had friendships with Koreans since the late 80's.
(That doesn't make me an expert on Korea, of course.)
How South Koreans react to the constant threats
For English teachers in Korea, it's fairly universal to be shocked at how calm the SKs are. They're more worried about what the USA might do, than NK or China. Especially since the fire & fury remark, reportedly.
The SKs have been under constant threat since the Korean War "ended." Occasionally, a military incident occurs. DPRK troops might shell a military boat on patrol, or a SK island. The SKs just grin and bear it, pretty much. They protest. Affected families are outraged. Nothing much happens.
The Kims have always tried to give off the sense of being unpredictable, but generally they've used the threats at their disposal to try to wangle assistance from the Chinese and, if need be, from the international community. They've been predictably "unpredictable".
Why NK threatens
NK can get oil & food from China since they pose a threat to China. China is overpopulated, as you know, and NK is a source of refugees. Did you know that in the region of China near Korea, that Korean is widely spoken? In those areas, there is a wide mix of Koreans, Chinese, and those who share both ancestries & perhaps speak both languages, or even an odd mix of the two. (You see the same thing in Europe, in Texas, etc.)
China does NOT want little brother DPRK to fail, not just because it would be embarrassing for another communist government to go belly up, but because how it would hurt China. It'd mean a HUGE influx of refugees. They don't want more NKs sneaking across the Yalu River into China. So they don't want another war in Korea, either, nor a regime change. China wants a stable DPRK to control the border.
So, it pays NK to be constantly making threats, and occasionally making good on the threats in a small way.
Guam, though, is no small thing. Kim JU knows if he attacked U.S. interests in any serious way -- and not just the small skirmish -- that any U.S. president
would respond. He doesn't want that. What he does want is to be able to threaten our cities, with the same threat we possess in our arsenal against his cities.
What can NK do, in terms of missiles and nuclear ICBMs?
At this point, NK's testing shows the state of their missile technology. They have
an ICBM that sometimes works, despite USA hackers, its immaturity, and the fact that they transport these liquid propelled ICBMs over bumpy roads. So far, they've only tested missiles in the East Sea (Sea of Japan). That suggests that their accuracy wasn't good enough to test near Guam, or they're afraid of the consequences.
Now, however, they threaten to lob 4 (unarmed) missiles over Japan, to splash down 30-40 km from Guam. That's new, and suggests their accuracy is improving, and/or their economic desperation is increasing, and/or they find it advantageous to test this POTUS. It's a risk for them. They'd be embarrassed if those missiles hit elsewhere, or if they actually hit Guam, or if they failed to get all 4 ICBMs to launch and re-enter.
We know about their nuclear yield, but not about miniaturization. Was the disco-globe that KJU posed with real? That would fit on an Hwasong-14 ICBM.
Why do so many South Koreans oppose missile defense?
Many South Koreans oppose
THAAD. Don't you think they'd appreciate the extra protection, or at least the chance of protection? That was my reaction.
There are some reasons why they feel this way, though:
- It could provoke an arms race. Let's say you're NK or China or even Russia, and you're concerned that THAAD is reducing your missile threat. What are you gonna do? Make more missiles. Bombard with even more.
- THAAD could lead to a false sense of security. It's only been tested by the USA, under careful conditions. How many failed tests have been swept under the rug? Has it ever been shown to be effective against NK's arsenal? Not yet.
- Anyone living near a THAAD installation will be under additional threat from traditional artillery, etc.
- The Chinese could react in negative ways: a trade war, a JFK-style blockade, or even intervention.
I'm neutral on THAAD, by the way. Personally, if I were still there, I'd prefer the possible protection. But I can see why it could provoke China and end up harming SK.