A letter from Albert Einstein to his best friend in which he criticises Neville Chamberlain’s appeasement of Nazi Germany is to be sold at auction.

One of a series of letters from the Nobel Prize winning physicist to Michele Besso in 1938, it outlines how Einstein thought Chamberlain – then British prime minister – was “naïve” to think Hitler would turn his attentions away from the UK.

Due to be sold by Los Angeles-based Nate D. Sanders Auctions, its covers Einstein’s reactions to world news in the days after Chamberlain returned from Germany with an undertaking from Hitler not to attack, declaring “peace in our time”.

To Besso, who together with Einstein was helping save European Jews, the genius wrote: “You have confidence in the British and even Chamberlain? O sancta simplicitas …!” The Latin phrase translates as ‘Oh holy innocence’ or ‘naiveté.

Of Churchill’s predecessor, who had just signed the Munich Agreement allowing Nazi Germany to annex Czechoslovakia, Einstein wrote: “Hoping that Hitler might let off steam by attacking Russia, he sacrifices Eastern Europe. But we will come to see once more that shrewdness does not win in the long term.”

The man whose equations helped pave the way for the atomic bomb then goes on to pen a withering rebuke of Chamberlain’s actions, noting the geopolitical consequences of the doomed policy of appeasement.

“In France, he pushed the Left into a corner and, in France as well, helped give power to those people whose motto is ‘Better Hitler than the Reds,’ wrote Einstein.

“The extermination policy against Spain already showed this clearly. Now he saved Hitler in the nick of time by crowning himself with the wreath of love of peace and inducing France to betray the Czechs.

“He did all this in such a clever way that he deceived most people, even you. His only fear, which spurred him on to his humiliating flights, was the worry that Hitler might lose ground. I do not have any hope left for the future of Europe.”

The starting bid for the letter on Thursday is $25,000, with other letters – including one on his divorce and one about his son’s mental health – also up for grabs.