Update: The letter sold for $31,000.I wouldn't claim to agree with all Einstein's political views – in particular, he was a leftist when it came to many issues – but it's still plausible that I would agree with "his side" in most of the actual conflicts he has fought.
The Express just revealed some cool newly surfaced letter:
you may buy a remarkable letter by Einstein for $25,000, unless someone offers more – so far there are no bids.
I killed Einstein, Gentlemen, a 1969 (post-occupation but filmed already from 1968) Czechoslovak comedy with some time travel. To retroactively prevent the already-real Bomb G that makes women hairy, they plan an expedition to Prague in 1911 where Einstein discovered some prerequisites for the bomb. If you speak neither Czech nor Spanish, you won't understand much. ;-) Note that e.g. at 9:35, they were already taking selfies using a selfie stick in the late 1960s – a Czech invention. ;-)
In October 1938, ten days after Britain and France betrayed Czechoslovakia, Einstein (who was at Princeton) wrote a German letter to his old friend from the patent office, Michele Besso – you must remember him from the National Geographic "Genius" series. It's the same Besso whose death was downplayed by Einstein's famous eternalist quote "People like us, who believe in physics, know that the distinction between past, present and future is only a stubbornly persistent illusion." ;-)
Recall that Einstein got a nice scholarly job in Prague in 1911 – so Bohemia was a rare place that appreciated Einstein's genius (much like we did it in the case of Nikola Tesla, by the way). He loved Prague, not so much the people in it. And Mileva hated it but she hated most other places, too. ;-) He was there for a year and returned to Prague in 1922-1923 for another year.
So you may imagine that Einstein knew something about Czechia and about the co-existence of German and Czech speakers, too. (After the war, he wrote a letter to the Czechoslovak communists, begging them not to execute Dr Ms Milada Horáková. The comrade's view didn't help: They hanged her, anyway.) The letter reads like a prophesy. Most obviously, Einstein stated "I do not have any hope left for the future of Europe" which was the right prediction done at the very right time – when many other people were clueless. With hindsight, I think it's clear that it was the two-stage donation of Czechoslovakia to Hitler that has made the Second World War inevitable.
The letter proves that Einstein understood – I think that totally correctly – that Chamberlain was the actual father of the betrayal of Czechoslovakia, even though it was only a formal betrayal by France which had a defense pact with Czechoslovakia. Moreover, he said that the logic could have been to establish peace in the Western part of Europe – while secretly hoping that Hitler could get weaker by a war with the Soviet Union.
Einstein also blasts the recipient, his friend Besso, for believing these appeasement fairy-tales and mentions some examples proving that Hitler isn't repelled by tough action against Western countries such as Spain and France. Needless to say, all these warnings turned out accurate within two years and Western Europe was actually attacked before the Soviet Union.
The auction ends in two days.