They have no food; South Korea has plenty. The main thing staying our hand, IMHO, is that North Korea remains a Chinese satellite and the US doesn't desire the direct military conflict confronting North Korea would cause (nor do South Korea or Japan). Unfortunately that merely raises the ante without otherwise changing the game; if China is less bellicose toward us, has committed less acts of war against us in the last decade than North Korea has against South Korea, it's only because the Kims are a tough act to follow. The dictators and autocrats know von Clausewitz well, however: They will, as others of their ilk before them, make a pretense of diplomacy so long as peaceful nations will cede their desires at no cost, but they know that even Chamberlain had his limit, consequently they constantly prepare for their inevitable war. At some point, in Seoul, or Tokyo, or Delhi, or Brisbane, someone is going to decide they don't want their own native Tiananmen Square, and at that point they will be reminded who first said, "political power comes out of the barrel of a gun". I pray they do not accept reality too late.

It should be an interesting decade or two. America no longer has the ability even if it ever had the desire to defend Europe from authoritarian regimes, and Europe has lacked the means since the '20s. Hopefully Putin remembers the Alamo as well as I do....