Ukraine was apart of the soviet union..gaining independence in 1991 after it collapsed.
Russia doesn’t want Ukraine joining NATO because the country is ethnically theirs short version. US will do nothing but sanctions
Russia doesn’t want any countries on its periphery joining NATO because it would bring the US/Western Europe too close to their heartland. It’s somewhat similar to China not wanting other countries to recognize Taiwan and eventually try to put military bases there. IDK how they’re going to deal with this.
If they speak the same language and are ethnically the same annnnd Russia can properly take care of them, then I see no issues. Ukraine should give up peaceful being as they used to be part of the Soviet Union. There’s not much the us can do anyway cause any direct attack on Russia is essentially world war 3.