Invasion of what? What's a North Korea? If Taiwan can't be recognised as a real country then there's also only one Korea that's partially occupied by a glorified cartel.
Hint: the one that uses the same methods of control as Los Zettas, and also competes with them in human and drug trafficking, money counterfeiting, etc.
The number of soldiers sent this time was estimated by the South Korean intelligence service to be between 1000 and 3000 soldiers. It doesn't make a dent to DPRK's military, and it also doesn't affect the war against humanity very much, because the Russia loses that many soldiers per day or two.