Hands clasped in friendship, Adolf Hitler and England's Prime Minister Neville Chamberlain, are shown in this historic pose at Munich on Sept. 30, 1938. This was the day when the premier of France and England signed the Munich agreement, sealing the fate of Czechoslovakia. Next to Chamberlain is Sir Neville Henderson, British Ambassador to Germany. Paul Schmidt, an interpreter, stands next to Hitler. (AP Photo)

After the final agreement with Iran over its nuclear program was announced in Vienna last week, references to one long-gone politician surged on social media: Neville Chamberlain.

This is not surprising. The late British prime minister, who presided over the ill-fated Munich agreement with Adolf Hitler in September 1938, is the metaphor of choice for all who prefer confrontation to mediation.

As my colleague Philip Bump noted, Twitter mentions of “Neville Chamberlain” spiked on July 14, with neo-con hawks and others on the American right lambasting the Obama administration’s supposed “appeasement” of the Islamic Republic.

[The Iran deal: How it works.]

The historical talking point centers on Chamberlain's negotiated pact with Nazi Germany, which granted Hitler the right to extend his rule over German-speaking areas of Czechoslovakia rather than risk the prospect of a full-blown invasion. In a speech delivered upon his return to Britain, Chamberlain quoted a phrase first uttered by an earlier 19th century British premier who had also conducted diplomacy with the Germans.

Europe, he said, borrowing words from former British Prime Minister Benjamin Disraeli, now had "peace for our time." He then exhorted his countrymen to "go home and get a nice quiet sleep."

If there's any doubt over how that contention sealed his fate in the eyes of history, just see the recent comments of prominent GOP politicos and presidential candidates.

For example, when President Obama had a brief, friendly encounter with Cuban leader Raul Castro on the sidelines of a memorial service for the late South African President Nelson Mandela in 2013, Sen. John McCain (R-Az.) was less than impressed. “Neville Chamberlain shook hands with Hitler,” the outspoken senator reminded listeners during a radio interview.

The deal in Vienna, agreed between Iran and six world powers, including the U.S., rankled presidential hopefuls, too. “This isn’t diplomacy, it's appeasement,” declared former Florida governor Jeb Bush last week.

On Tuesday, Sen. Lindsey Graham (R-S.C.) said Obama was the "Neville Chamberlain of our time."

[Don't forget how the Soviet Union defeated Hitler.]

Neville Chamberlain’s mistake – acceding to a territorial compromise that did little to check Hitler’s continental aggression – is seen as a kind of original sin, a fatal act of foolishness and moral cowardice that had to be redeemed by nobler, braver men in the hideous years to come.

“This is the greatest appeasement since Chamberlain gave Czechoslovakia to Hitler,” said Sen. Mark Kirk (R-Ill.), reacting to the Iran deal last week. “[President Obama] is doing this because of his very poor understanding of history and what happened to Neville Chamberlain.”

Today’s “appeaseniks,” Kirk and his allies argue, are either blind to or deluded about Iran’s evil ambitions, like Chamberlain supposedly was eight decades ago.

But beyond the crude flimsiness of the analogy (Obama is patently not Chamberlain, and Iran does not pose a fraction of the threat represented by Nazi Germany in the late 1930s), WorldViews reckons Chamberlain also deserves a fairer hearing.

A scholarly consensus has emerged over time in the wake of World War II revising the image of Chamberlain as a feckless, blundering dove.

“Chamberlain made mistakes in the 1930s. He overestimated his ability to reach a settlement with the dictators; he probably clung too long to the hope of averting war,” writes British historian David Dutton. “But it is doubtful if anyone else would have done much better, [Winston] Churchill included.”

[The dark side of Winston Churchill.]

Indeed, Chamberlain, a conservative politician with a long, accomplished political career and a reputation for intelligence and hard work, was operating in a very fraught context. The painful memory of World War I -- a continental disaster -- was still fresh in Europe and guided the thinking of many its leading statesman.

Nor was the Nazi regime, in a time before its concentration camps and wartime atrocities, seen in such a monstrous light. It commanded sympathy within the corridors of power in Britain and in the United States, which was even more aggressively trying to avoid Europe's simmering maelstrom than the British under Chamberlain.

Here's Dutton once more on some of the underlying realities guiding Chamberlain's actions:

Chamberlain was no fool. But no individual could change the basic facts of the international scene, which made fighting Germany almost unthinkable for most of the decade. Like all his generation, Chamberlain had been deeply scarred by the memory of the First World War. Expert opinion predicted that any future war would be even worse: to the slaughter of the battlefield would be added unspeakable destruction from the air. Extrapolating from the Spanish Civil War, it was estimated that the first few weeks of a German air assault would bring half a million casualties: Britain was defenceless in the face of the bomber.

Moreover, there were fears overall about Britain’s military preparedness in 1938, as Nick Baumann, now an editor at the Huffington Post, detailed in a 2013 article in Slate:

In March 1938 the British military chiefs of staff produced a report that concluded that Britain could not possibly stop Germany from taking Czechoslovakia. In general, British generals believed the military and the nation were not ready for war. On Sept. 20, 1938, then-Col.Hastings Ismay, secretary to the Committee of Imperial Defense, sent a note to Thomas Inskip, the minister for the coordination of defense, and Sir Horace Wilson, a civil servant. Time was on Britain’s side, Ismay argued, writing that delaying the outbreak of war would give the Royal Air Force time to acquire airplanes that could counter the Luftwaffe, which he considered the only chance for defeating Hitler. British strategists, including Ismay, believed their country could win a long war (so long as they had time to prepare for it). This was a common belief, and doubtless factored into Chamberlain's calculations.

Time, though, was not on Chamberlain's side. His overture to Hitler in 1938 was framed less as a strategic error than an act of "dishonor," as his political rival Winston Churchill put it. Yet even after Chamberlain was compelled to resign his post in 1940, he served in important roles in the country's government until his death from cancer later in the year.

Chamberlain stood by his record in the last phase of his career and life. The following is from a speech he delivered in 1939, justifying his methods of appeasement. It displays both idealism as well as a certain pragmatism:

Armed conflict between nations is a nightmare to me; but if I were convinced that any nation had made up its mind to dominate the world by fear of its force, I should feel that it must be resisted. Under such a domination life for people who believe in liberty would not be worth living; but war is a fearful thing, and we must be very clear, before we embark on it, that it is really the great issues that are at stake, and that the call to risk everything in their defense, when all the consequences are weighed, is irresistible.

Chamberlain worked hard to stave off a war and, set against that truly "wicked man" Hitler, could not. "It's not such a bad epitaph," Baumann concludes.

In October 1940, just weeks before death, Chamberlain expressed optimism about how he would be remembered in the years to come.

"On the whole,  although I have in a sense failed in everything I set out to achieve," he wrote, "I do not believe that history will blame me for that." At least on this count, Chamberlain was most definitely wrong.

Read more:

Iran deal: What they said. What they got.

How not to write about Iran

Israel slams Iran deal