“I’m not happy with what Putin is doing. He’s killing a lot of people, and I don’t know what the hell happened to Putin,” said Donald Trump on Truth Social over the holiday weekend.

“I’ve always had a very good relationship with Vladimir Putin of Russia, but something has happened to him. He has gone absolutely CRAZY! He is needlessly killing a lot of people, and I’m not just talking about soldiers. Missiles and drones are being shot into cities in Ukraine, for no reason whatsoever.”

Trump is not the only president who has stressed the importance of personal relationships with other nations’ leaders. But even the most sympathetic relationships have been frayed by national interests rooted in history. Margaret Thatcher and Ronald Reagan had rough patches over the Falklands and Grenada.

It seems possible that Reagan and inconceivable that Trump read Harvard historian Richard Pipes’ volumes on Russian history, showing how the rulers of tiny Muscovy, starting with Ivan the Terrible, constantly expanded their domain over the featureless north European and Ukrainian plains, seeking ever more land and peoples as a buffer for those they already held.

Reagan appointed Pipes to his National Security Council and, as a close but secret follower of geopolitics (the movie magazines wouldn’t have understood), observed Joseph Stalin’s postwar expansion of Russian military suzerainty westward. When asked why he was bent on heading toward the Rhine, Stalin supposedly answered that Tsar Alexander I, after defeating Napoleon, took the Russian army all the way to Paris.

So Putin’s assault on Ukraine, Russian territory from the time of Catherine the Great (Alexander’s grandmother) to the fall of Mikhail Gorbachev, was an expression of a historic national impulse likely popular among his nation’s ethnic Russian majority.

Trump’s seeming astonishment that Putin “is needlessly killing a lot of people … for no reason whatsoever” shows a reassuring horror at mass slaughter but also an innocence of knowledge about Putin’s career.

In his 2004 book “Darkness at Dawn” and in later writings as well, Russian expert David Satter has written that Putin, the former KGB agent and aide to Saint Petersburg mayor Anatoly Sobchak, arranged the 1999 bombing of four apartment buildings, killing 300 people, and blamed them on Chechen rebels.

To attack them, Boris Yeltsin appointed Putin prime minister and then resigned in return for pardons for him and his family. Putin promptly won the first of several elections from a wary electorate (which I observed briefly as a reporter in Moscow) that hoped he would be the “strong hand” that many have traditionally believed Russia needs.

That such a man would lodge the war’s largest drone attack on Kyiv and Ukraine last weekend should not have come as a shock. Yet Trump is not the first American president who has seen Putin as just another politician whose not unreasonable concerns could be appeased.