In 1938, there was a saying, "...there are those who support Stalin and those who support Hitler. There is no third choice."
...there were those who didn't support either one but saw hitler as the most immediate and deadly threat.
The U.S. has pledged to defend members of its NATO alliance. It has no obligation to get involved in a war between two former Soviet states.
...Budapest Memorandum. Ukraine gave up their nukes for a promise of security against russian hostility by UK and US.