I agree with both of you.
Honestly right now, I'm not too concerned about Chinas immediate threat. They're still in a fairly vulnerable state, their economy is still geared heavily towards export, the gap between the coastal cities and inland is still vast, and the central government is still clearing house and resettling itself after Xi took over.
However, in about a decade, the PRC will be in a position to start using hard power in the Pacific if it chooses to do so. Now I don't think it'll be quite like Japan since the PRC, whilst a dictatorship, is not a primarily military based one, it's more focused around business and economic growth, and war harms both of those. However, war is also a good distraction from internal problems (ask Argentina) particularly if it is a war against an old enemy, ie Japan.
Japan itself is in a very awkward position, it needs to drop Article Nine of the Japanese Constitution and rearm itself to counter Chinese military expansion, but it's still got the shadow of the 1940s hanging over it, and if Japan starts to rearm, Chinas military expansion will go into overdrive, and South Korea will join the arms race and tensions will rocket. So Japan is forced to rely on America, who is also currently facing tensions in the Middle East and Eastern Europe and so has to spread its forces thin, forces that the US can't really afford to field, but it has to because no-one else can afford to field such firepower either. Europe probably could but its too busy politically fighting itself to actually do anything unified, and whilst the Middle East Coalition has put forward a fairly good show, it's still vastly below what is needed to tackle Daesh, not to mention the groups in Somalia, the resurgent Taliban and Al'Qaeda sitting in the shadows licking its wounds.
There's a hundred bush fires going on, and the US is the only one who has firefighting equipment and the co-ordination to use it.
It's little wonder that Obama has aged so much in ten years...
