(1) Upon coming into office, he initiated the famous “reset” to undo the “drift” in relations that had occurred during the George W. Bush years. But that drift was largely due to the freezing of relations Bush imposed after Russia’s invasion of Georgia. Obama undid that pushback and wiped the slate clean — demanding nothing in return.

(2) Canceled missile-defense agreements with Poland and the Czech Republic. Without even consulting them. A huge concession to Putin’s threats — while again asking nothing in return. And sending a message that, while Eastern Europe may think it achieved post-Cold War independence, in reality it remains in play, subject to Russian influence and interests.

(3) In 2012, Obama assured Dmitry Medvedev that he would be even more flexible with Putin on missile defense as soon as he got past the election.

(4) The Syria debacle. Obama painted himself into a corner on chemical weapons — threatening to bomb and then backing down — and allowed Putin to rescue him with a promise to get rid of Syria’s stockpiles. Obama hailed this as a great win-win, when both knew — or did Obama really not know? — that he had just conferred priceless legitimacy on Bashar al-Assad and made Russia the major regional arbiter for the first time in 40 years.