I think there is very little risk of a war breaking out. First, I doubt America would allow either of the two nations to actually go at it. If they DID, then North Korean, Chinese, Russian, and American involvement would be inevitable and I can't see that happening.
As others have pointed out, the publication in question is trash and has no real value or influence. I will say that after 10 years in Japan, it feels like nationalism is on the rise. Whether this is a result of white-washing the textbooks, backlash against the gradual rise of non-japanese, or some sort of misplaced nostalgia - it's a bit unnerving. I don't think we'll see anything really change on that front in the next 5 years, but some of the newer, upcoming politicians could change the political landscape in a decade or so. I think Japan's best chance is to keep progressing down this multi-cultural society that they're being dragged into. The more they assimilate other people and cultures, the more flexible they'll (hopefully) become. The signs that this is possible are there, but there's still plenty of stuff to be concerned about.
US foreign policy in Asia has shifted quite a bit in the last few years... Already the US is getting ready to pull all the way out of Okinawa, something that would have never happened in the 80s 90s or 00s...
Are you sure about this? I know Okinawa has been quite vocal about getting American troops off their island, but the US response from what I've seen on the news has basically been "lol, no."
Japan has decided to switched to non-nuclear power from now on.
There is a growing vocal minority that opposes nuclear power, but the government has been doing a good job of quietly sweeping the matter under the rug. If anything, they're actually bringing power plants back online for pretty laughable reasons. There is little, to no transparency about the matter. Very little in the way of investigative reporting. News publications know that if they ran with anything they'd be ostracized from press clubs (the new organizations that the government feeds information to) so no one wants to dig around for the truth. It's a huge problem. I want to say that there is so much wrong with this country on a fundamental level (in terms of the government and basic human rights), but I'm speaking from a western perspective so who's to say I'm right.