I agree with you Timur, so here's my rant from someone who typically loves this kind of stuff. I just watched the trailer that gives a more detailed background and the story is way too far-fetched to even be considered "speculative fiction." A successful invasion of the South by North Korea is barely plausible without Chinese intervention, but the Chinese would likely avoid direct involvement in an effort to avoid World War III. A second Korean War would be costly, but NATO would probably have the upper edge, even with American economic trouble.
But since North Korea wins in 2015 (perhaps the EU and NATO suddenly disappeared), we are to assume that they are able re-strengthen the military, repair the economy, and take advantage of South Korean technology and industrial capacity to successfully annex Japan by 2018. That's impossible, I'm sorry. They must have some kind of alien technology (oh, that must be the twist) to be able to produce the fleet and air force necessary to carry out an invasion of the United States. The United States Navy's newest aircraft carrier and the first of its class, CVN-78, had her keel laid in 2009 and should be available by 2015. She's being built with the best production technology the U.S. have to offer. If the North Koreans, and even Chinese, can pump out a whole fleet out in a decade, then I don't know what to say.
