In his NATO news conference today, President Trump held President Obama responsible for permitting Russia to encroach on Crimea, and said:
“Long before I got here, President Obama allowed that to happen. That was on his watch, not on my watch. People like to say, oh, Crimea but the fact is they built bridges to Crimea; they just opened a big bridge that was started years ago, they built I think a submarine port, substantially added billions of dollars.
“So, that was on Barack Obama’s watch. That was not on Trump’s watch. Would I have allowed it to happen? No, I would not have allowed it to happen.”
Note: Trump is correct: both the building of the bridge linking Russia and Crimea, and the Russian militarization of Crimea, including the revamping of its naval base there, began during Obama’s second term. Obama failed to stop it, if he even tried.