The previous president was impeached for taking aid from ukraine lest they investigate invented allegations of corruption.
That putin warned of something is meaningless. Are we expected to roll over whenever a foreign country makes a threat? Most of these threats are empty; even when they aren't, some things they have no right to threaten us about. A country arming itself to protect from a (demonstrably) belligerent neighbour is one such thing. I'm surprised people eat this ridiculous excuse from putin so easily.