In 2008, a Chinese admiral suggested to Admiral Timothy Keating, then commander of US forces in the Pacific and Asia, that China and the U.S. split the Pacific Ocean between them on a line running through Guam. The proposal was that the Chinese navy would be responsible for the western portion and the U.S. Navy would be responsible for the eastern portion. Admiral Keating responded by saying that the U.S. would not be pushed out of the western Pacific.
China always deports North Koreans who have managed to escape their totalitarian nightmare. It is in the process of deporting more, as it has done so often in the past, trying to eliminate the underground railroad which assists North Koreans. It could easily send them to South Korea, but doesn't. China is in violation of a number of treaties in doing so.
The UN Refugee Convention was originally drafted in 1951, with a 1967 Protocol. China signed both in 1982. China signed the Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment in 1987. These treaties expressly forbid the deportation of refugees back to a country where they will be tortured, imprisoned, and executed, which is exactly what happens to North Koreans when they are returned to the DPRK.
Tillerson, the former Texas oilman, might be thinking of North Korea's oil and gas potential.
Foreign Policy trumpeted that "North Korea Is Practicing for Nuclear War ... preparing for a nuclear first strike," but the article itself was more realistic, noting that the DPRK launched a missile into the sea and then revealed that the distance traveled was the same as for Busan, South Korea's second-largest city.
Kim Jong-un is not suicidal, however, He would never launch a first strike, but he would launch one at the first sign of a ROK and U.S. invasion. And one thing that is not often mentioned is his desire to reunify the Korean peninsula under DPRK terms. This was the goal of his grandfather and father, and if anything, he is more like his grandfather than his father. After securing the South, he'd be able to triple the size of his labor camps.
We have three choices in North Korea
1) We can allow the DPRK to reach a point where it has missiles accurate enough to reach anywhere in the world, with nuclear warheads small enough to ride along. No one knows when the DPRK will have this capacity, but it won't be that many years from now. Then we can either donate all the luxury goods Kim Jong-un wants or start WWIII. Reunification will occur on DPRK terms, with a severe effect on the world's economy, given how economically strong South Korea is. This is the policy right now.
And we should remember that Kim Jong-un might not be satisfied with threatening the U.S. with missiles. The next logical step would be to develop suitcase nukes, perhaps even partnering with Islamists, who of course would not be satisfied with mere threats. Just imagine the reaction to a tweet of a suitcase nuke with the Brooklyn Bridge in the background.
2) We can launch a massive strike, and I do mean massive, given that there are anywhere from 10,000 to 20,000 artillery pieces located within range of Seoul. The DPRK has stated that this artillery can launch nuclear shells, but I suspect that its development has not quite been perfected. The DPRK has plenty of chemical munitions, however, so it could still inflict hundreds of thousands of casualties in the first hours of an attack. And soon the DPRK will indeed have nuclear shells. We would need to destroy all of this artillery, a difficult task given that they are entrenched in bunkers. Even if we sent all of our carriers to the area, we still wouldn't be able to drop enough bunker busters in time. We'd also need to destroy all airfields, missile launchers, both fixed and mobile, tanks, etc. In other words, the job is too big even for the combined might of U.S. and ROK forces. Sure, we'd win, but South Korea, Japan, Hawaii, and a few other places would suffer horrendous casualties. And it just might trigger WWIII.
3) We can twist China's arm into making the DPRK compliable. China has a great deal of leverage over North Korea, given that it supplies North Korea with most of its oil, as well as food and electricity. China could cause an implosion within one winter. But its self-touted ban on North Korean coal is mere lip service. Most of the luxury goods for the North Korean elite pass through the porous Chinese border, with China only inspecting 5% of the trucks entering the country. But we won't give China an ultimatum, i.e. eliminate Kim Jong-un or we'll close our ports to Chinese goods, because the Walton family, Jeff Bezos, Tim Cook and other greedy outsourcers are raking in too much loot.
"North Korea relies on China for survival. If China cut the fuel supply across the Yalu River which is between North Korea and China, then the regime ... will collapse in a matter of weeks. So Beijing plays a very crucial and vital role in the Korean Peninsula," said Xie Yanmei, senior China analyst for the International Crisis Group in Beijing.
But similar to how time is running out on #1, it's also running out on #3. China has been very busy over the last twenty years, stealing and finagling technology to build its own high-speed railway, airliners, processors, weapons systems, and other essential technology. Our leverage is disappearing like the grains of sand in an hourglass.
There might not be a happy ending.