Japan is never going to voluntarily attack China. Even if there was a desire to, they know they could not win. Any military build up by the former is due to fear of the latter.
Japan probably won't not attack China (I don't see why they would, not proactively at least), that's not what was being asserted. Japan however may defend Taiwan or allies/neighbors in the south china sea should things go hot there elsewise. And Japan have stated at least some interest in doing so which means that if China wants Taiwan, they might have to contend with japan.
These sort of things can work as a deterrent as much as power projection, and they don't have to get into direct violent/physical conflict for there to be diplomatic tension/worsening of relations as a result. I'm not saying this is most effective use of Japan's resources or focus or that China is for sure going to do anything or making any other such claims, just explaining the potential rational for why China would be non-plussed at Japan over F35 purchases even if they don't feel Japan is gunning for them.
Of course, if china has no actual wartime intentions in Japans sphere of influence, then yeah, they probably give much less of a shit. So depends on what their intentions really are as to how they feel about it. The fact that they're publicly broadcasting displeasure is probably not a sign that they're cool with it though.
Any protest from China is just painting themselves as being in a defensive position, whilst they make claims over the oceans and territories that the international community disagrees with. Very much not defensive acts.
Building up submerged reefs to military bases, harassing the Philippine navy regularly, massive fishing fleets strip mining the sea all over the world, melee weapon skirmishes with Indian soldiers in Kashmir ?
China has been strategically preparing to do it for years now. It's not just talk from a crazy leader of a democratic country that will be gone in a few years, but is on the official roadmap of a dictatorship for at least a decade.
You don't have to drop bombs to invade. If you think China's not invading with its economic policies and activity alone, you're not paying attention. I'm in no way saying western nations are not guilty of the same and worse behaviours (look at how many legitimate governments have been toppled and sanctioned for daring to go against the USA), but China is not friendly.
Because they ultimately are managing better in the 21st century than any other country. America had its peak from 1945 to 2001. Britain ran the world in the 19th century. China is the new global superpower.
In an ideal world America would have managed to keep a bipolar world going, but it has decided to abandon that in favour of short term boosts.
It does, and I already wrote about western countries being just as guilty of invading, if not more so. None of what you wrote contradicts my point that China is actively expanding and using mainly economic tactics to do it.
It's wild that people say this. Japan attacking China (and later the Western colonies, and later the US) knowing that it could not win was one of the most important events in the 20th century. There isn't a country as infamous as Japan for starting wars it cannot win.
Also that attack happened on Sept 18, this very day, in 1931.
Not so wild when you realise that it's not the 1930s, and Japan isn't being led by an imperialist & expansionist regime. I'm not denying any past aggression from Japan, my grandparents fought them, but the situation is quite different now.
Japan is very much still jingoistic today, and Jingoism is what drove the Lugou bridge incident and the seconds sino-japanese war. While it was imperialism that drove the invasion of Korea and Manchuria in 1931, with a real need for resources and to give land and slave to industrialists, the 1937 war was totally dumbfuckery from jingoist sentiments. Basically Trump, but supported by 85% of the population.
That's why fascism doesn't work btw. They end up believing their own lies and do the most egregiously idiotic shit.
All of the people responsible for that are dead now. Every single one. Maybe there are still 100k people alive that were ~5yo at the time, but I don't think we can hold them culpable.