So why is that what makes China so bad? Like most things China is accused doing of the US has done worse.

Original brainchild for Lebensraum explicitly points to Manifest Destiny: https://encyclopedia.ushmm.org/content/en/article/lebensraum. You can slap “lebensraum” and “manifest destiny” into google and also see the results for yourself. I admit say I’m not a well of primary nazi sources if that doesn’t satisfy you.

He cites Manifest Destiny as what the German people should do to eastern Europe and allegedly based the brownshirts on the KKK.

filled with mass propaganda and nationalism

Yo we got that too in America.