Obama clearly wants to pull the U.S. out of Iraq and Afghanistan, which under Bush were big parts of the U.S. empire.

Clearly. And for a good reason, given how Afghanistan has always been resistant to external aggression and Iraq was Bush and Cheney's pet project, unrelated to 9/11.

Lots of Republicans think that Obama wants to greatly reduce U.S. military power

What do they think his motivation would be, other than possibly financial?

I take it you don't have much experience talking with leftwing college professors.

Some. The ex-hippie Berkeley types are rather annoying. Krugman is annoying. But to me any ideologically-motivated argument is annoying, because of its anti-rationality.

It's far from implausible to think that deep down Obama believes that U.S. military power has, with the exception of WWII, been a force for evil.

Eh, I don't see the connection. The leftwingers rarely hide their views. Obama has never expressed anything close to what you are describing and hasn't worked for any radical leftwing organizations (beyond a tenants' rights organization during his college years). He certainly supported left-leaning causes, like healthcare and welfare reforms, in the past, but he still does so, pretty openly. I grant you that his expressed views and actions have shifted rightward, and his actual views might be closer to what he held 15 years ago, but still solidly within the spectrum of DNC views. The odds of him considering the US military power being (a force for evil), given that he never expressed views like that, are pretty slim. Not that I personally approve of his policies and actions, the man has been a disappointment in terms of his competence level. But inept does not mean malicious.

Obama clearly wants to pull the U.S. out of Iraq and Afghanistan, which under Bush were big parts of the U.S. empire.

If Iraq was ever part of the U.S. empire, we might have done what it took to govern it, and would be getting cheap oil from Iraq, which I thought was just a fantasy of the left. Maybe you'd like the U.S. to act as an old fashioned Empire, but nobody except maybe Dick Cheney wants to do that. It might work but I doubt it, but most important it has no chance of happening and if part of your critique of Obama is that he's not an old fashioned imperialist, I think Teddy Roosevelt might have been the last American one.

Putin is former KGB and the KGB had a long history of getting leftwing intellectuals to spy for them because the intellectuals disliked the West.

Today's "left wing" intellectuals are blatherers. Postmodernism is anti-Enlightenment and views Marxism as an unfortunate result of the Enlightenment the same as capitalism. Noam Chomsky calls himself an anarchist. They tend to be anti-everything when it comes to actually doing something. And Obama is certainly nothing like that crowd. There is no international Communist movement, and there's been virtually none since Brezhnev, though the USSR ran around trying to buy a lot of countries. If you want a clear picture of the era of "Red Intellectuals", read Witness by Whittaker Chambers, and then I suggest Reds: McCarthyism in Twentieth-Century America by Ted Morgan (despite the subtitle, McCarthyism is less than half of what the book covers). Chambers was the star witness for Nixon's "pumpkin papers" trial. Both cover a lot of just how deep the international Communist movement got into America, and Chambers writes beautifully and helps you to see why that was. He also speaks for the many who became deeply disillusioned by the Hitler-Stalin pact. I used to think that was odd because in my view it was a very natural reaction to Chamberlain's Munich, but the Communists really did put up a very good show of defining and opposing the Fascists (I say "a good show" for a reason but it's too complicated to say more), and for as long as that was true, a lot of people put a halo on them for that, then many of them because naively heartbroken.