A foreign head of state threatening to invade and annex their sovereign territory.
How would you feel if Xi Jinping threatened to invade and annex Hawaii because he felt he needed it for security?
No, but it should be our goal to be respected by them, which requires behaving in a respectable manner. Threatening an ally with invasion and occupation of their land is not a respectable thing to do. That's exactly what Putin does. And that's why civilized people generally don't respect Putin.
Nobody here said boo until Trump started talking about taking Greenland from Denmark. Most people here don't really care about politics, but Trump's threats against Danish territory really pissed off a lot of people, and rightly so. If Americans find it unacceptable for Putin to annex parts of Ukraine and for Xi to annex Taiwan, why should the American president be held to a different standard? Is that so hard to understand?