I doubt he will "attack," it's more likely he will just continue to engage in more saber-rattling.
But for argument's sake, let's say he does some sort of strike? I doubt it would start WWIII.
In the first place, despite all the anti-Russia rhetoric from the Progressive-left, Putin's Russia still seems positive towards this Administration.
In the second place, China is getting a bit annoyed by the extremism of North Korea which under the Kim family leadership has become more rogue rather than obedient satellite for their tastes.
If a strike was surgical, limited, and clearly military target oriented (like nuclear launch facilities) I think China would rattle their sabers but be satisfied with that unless North Korea responds with outright war.
Even then, they may be willing to sacrifice North Korea for a peace where U.S. forces are finally removed by a united and possibly influenceable democratic Korea under southern leadership.
I agree with most of that. I think the nature of the military forces the U.S. has been moving toward Korea offers some clues. The Vinson group has returned home. The SSGN Michigan is probably still near Korea. A few days ago, the Nimitz arrived in the Seventh Fleet's area--likely somewhere near Korea--with a cruiser and four destroyers. Last I heard, two of the Reagan's four destroyers were near Korea, with Reagan itself, a cruiser, and the other two destroyers having just finished a visit to Singapore. Before long, these ships will probably head back toward Korea.
The ten surface ships in the Nimitz and Reagan strike groups have a total of slightly more than 1,000 missile cells. Many of those are usually loaded with air-defense missiles, and some with antisubmarine missiles. But if the proportion of those cells loaded with cruise missiles is the same as on the two destroyers which launched the attack on the Syrian airbases--thirty-plus percent--there are more than 300 Tomahawks in the two carrier strike groups. Each carries a bomb of about 1,000 lbs.
Tomahawks are very hard for radar to detect, which suits them to surprise attacks, particularly on airfields and both antiaircraft and ballistic missile sites, and the Michigan can carry 154 more of them. The Michigan also is designed to carry quite a few special forces and their equipment. These forces might be involved in raids on sites where nuclear weapons are stored. There are only four SSGN's, but North Korea has to consider the possibility the U.S. has one near each of its coasts. The nature of these naval forces, when combined with the standing threat to any target in the world posed by B-2 bombers based in the U.S., presents North Korea with the threat of a surprise attack meant to eliminate its most dangerous offensive weapons and leave it unable to defend its airspace.
It's also interesting that several of the destroyers involved have radars and missiles which are capable of intercepting even medium-range ballistic missiles. That suggests the U.S. is also considering the less drastic measure of shooting down one of North Korea's test launches. These anti-missile missiles may not be completely reliable, but any lack of certainty could be made up for by firing, say, a dozen of them at the target. If that happened, Kim would have to decide whether he dared to retaliate and invite an attack by the other air and naval forces I mentioned. So, these forces put pressure on him to restrain his ballistic missile efforts that he was not feeling a few months ago. He has not had to worry about the large U.S. force in South Korea, because it was designed to deter another 1950-style invasion, which he does intend to make anyway.
