Crimea in U.S. military thinking.

All the financing of Maidan in Ukraine was driven by one particular goal, for which the U.S. State Department spared neither suitcases with dollars, nor cookies from Mrs. Nuland - Crimea. American missile defense system in Crimea would close the entire South and South-West Russia from the possibility of using ballistic missiles that serve as a deterrent to so-called American preventive nuclear strike. No coincidence that the much-touted project of European missile defense, which badly battered the nerves of our politicians and military, has flopped after the restoration of status quo in Crimea.^[1]

I have observed in the past that had the U.S. wanted Russia to relax about events in Ukraine it could have provided assurances that the U.S. had no designs on Crimea. A useful analytical tool applies in spades here, namely, "if you want to understand what is going on, focus on what is NOT being said or done." The U.S. "forgot" to make clear what its intentions were regarding Crimea so we can assume that they were nefarious.

It's beyond obvious that the earlier U.S. concerns about countering the threat of Iranian missile attack were a pretext.

Notes
^[1] "How Russia Ruined American Plans in Crimea." By Viktor Sokirko, Ft. Russ, 3/19/16.