Is not about Russia owning the neighboring countries. What she was saying is that Ukraine is a buffer country between NATO and Russia. Russia sees NATO as an enemy. If Ukraine joins NATO, Russia would have their enemies at the border and that would force a conflict with Russia.

I do not like Tulsi but she is correct here. However, I have a gut feeling that Putin wanted this conflict and pushed for it from within Ukraine. He encouraged Ukraine to join NATO to give him an excuse to move in.