Why do the Japanese/Chinese purchase USD over the Euro?



I took a look at the USA's bond holders, and the vast majority of our
dollar-denominate bonds are with the Japanese and Chinese.

Why do they crave dollars as opposed to the Euro? There are more
euros in circulation (higher market cap), and it's therefore a more
liquid investment. Also, the European area is also hungry for Eastern
Asian goods (i.e. Hondas, and remote controls). Why do the Eastern
Asians target our currency to raid?

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