Rationale:(a) The US leads NATO(b) That NATO agreed to invite...

Rationale:
(a) The US leads NATO
(b) That NATO agreed to invite the Ukraine to be a member despite France , Italy, Spain etc objecting
. on the understanding that that would lead to a Ukraine/Russian war.
(c) The US supported the Maidan 'revolution/Coup"

(d) the US followed up by being the biggest external supporter of the Ukraine
. in financial backing and arms.

So forget about the spin and the propaganda...that's simply the guts of it.