expatlife26:

The way that Japan is ww1 was described in that program and my further reading was just being really opportunistic. Germany had a bunch of holdings in China and in the pacific, but not a massively powerful global navy like the UK.

So Japan kinda got the idea that if they declared war on Germany, that it was win-win for them. They could take over Germany's possessions and then even if Germany/Austria-Hungary won the war there wasn't really a ton those countries could do about it. Worst case a victorious German/Austro-Hungarian navy retakes Tsingtao and the couple other little bases they might have had. But they wouldn't have been able to say...blockade Japan until they paid a huge indemnity.

Whereas if they wanted to seize British possessions, once the war was over they would have to contend with the British Navy. And that was a global power. UK could have locked down Japan pretty much indefinitely.

So I think for Japan it was just a risk/reward assesment. Get themselves a nice little colony on the Asian Mainland.

The Chinese at the time probably didn't hugely care whether Japan or Germany owned that city. I'm sure they felt a lot of impotent resentment.

China never took part in any combat, but they were officially on the side of the Entente, so technically on the same side as Japan. They sent units of laborers to Europe. To do the thankless stuff like digging trenches carrying supplies.