This summer's superhero flicks were interrupted by "Dunkirk," a searing film about real, everyday heroes rescuing British and French forces, and by extension, civilization itself from fascism. Looming large but off-screen is Winston Churchill, whose soaring "We shall fight on the beaches" speech isn't heard in the prime minister's voice, but read aloud by a war-weary evacuee.

In "Darkest Hour," debuting locally on Friday, Churchill (an excellent Gary Oldman) delivers that speech in a dramatic denouement to a perilous period of military defeats and political infighting.

Churchill is rightly depicted as an extraordinarily confident, competent wartime leader who despite personal and political flaws rallied the United Kingdom and united defenders of democracy worldwide to win World War II.

Unlike any current leader, Churchill's iconic status spans nations and ideologies: In just one example, no less a leftist than Bernie Sanders named Churchill, who led the Conservative Party, as his most admired foreign leader. Indeed, he's held up by Brits, Yanks and people of many nations who yearn for his ability to concurrently reflect and rally his citizens.

"Churchill was the eternal optimist — no matter how bad things looked he always had the energy, the verve, the courage to bear up," said William T. Johnsen, who holds the Henry L. Stimson Chair of Military Studies at the U.S. Army War College. "He personifies this idea that Britain will never surrender no matter how dark it gets — 'we will fight on to the end' — he gives a tremendous morale boost to the general populace, who I think was more in tune with Churchill in terms of wanting to fight on than some of the other leaders."

This split between Churchill's will vs. voices calling for negotiations with the Nazis (personified, but not limited to, Neville Chamberlin) is depicted in "Darkest Hour." And in an honest accounting, even the leonine Churchill considers conceding to peace talks. But he's steeled by British resolve, which he in part creates.

"He made them believe that they were equal to the fight," John Watkins, an English professor at the University of Minnesota, said in an e-mail exchange. Watkins, an insightful scholar of British history, society, and literature, added: "In speech after glorious speech, he reminded them that they had defended this island in times past, and would defend it again with great success. Above all, he believed, and he made them believe, that British civilization was worth fighting for."

As for Churchill's view of his fellow Brits, Watkins said: "He saw them as the greatest people who have ever walked the face of the earth, the greatest guardians of civilization itself, the ones who got it right in terms of politics, religion and civilization. And he also saw them as a nation, certainly not of belligerents, but of warriors capable of defending against aggression."

Such a full-throated assessment of one's country, let alone the West, is less audible on both sides of the pond today. In fact, divisiveness defines the U.S. and U.K. sociopolitical dynamic, which in turn is eroding the special relationship between America and Great Britain.

That fact was seen most recently in President Donald Trump's reckless retweet of three virulent videos (one discredited) from an extremist anti-Muslim movement called "Britain First" — rhetorically redolent of Trump's "America First" ethos, which echoes the isolationist movement that delayed America's entry into the essential war.

The president's careless, callous action drew a rare rebuke from Prime Minister Theresa May, and a British public engulfed in its own highly divisive debate over Brexit united in revulsion of Trump.

As for May, on Friday she finally brokered a deal on the Irish border with a niche Northern Ireland party that's part of her shaky coalition government in order to advance Brexit negotiations with the European Union. It was a small win for May in a much larger loss for Britain, which is pulling back from the very nations Churchill fought to save.

May might suffer in comparison with Churchill, but Watkins said that "the much more obvious, and damning, yardstick is [Margaret] Thatcher, whom she sometimes tries to imitate and then falls dismally short."

As for Churchill, even his wartime American comrade-in-arms hasn't held the public's imagination like the British leader. While Churchill "has become an icon of stalwart resistance against Hitler," Watkins said, "We probably know a bit more about FDR, but his greatest legacy, the U.S. welfare state — such as it is — has always been an embattled one."

Johnsen suggested that Franklin Delano Roosevelt's generosity in spreading credit helps explain how Churchill eclipsed FDR in the public's imagination. Churchill, he added, also outlived Roosevelt, and "was famous for saying 'history shall be kind to me for I will write it.' "

Which he did, earning a Nobel Prize in literature in 1953 "for his mastery of historical and biographical description as well as for brilliant oratory in defending exalted human values."

Scores more have penned their offerings in the oeuvre about Churchill, and compelling films such as "Darkest Hour" will refresh memories or introduce a legend. And unless and until a current-day leader shows the guts and grit and greatness of Churchill's wartime tenure, his iconic stature will only increase.

John Rash is a Star Tribune editorial writer and columnist. The Rash Report can be heard at 8:10 a.m. Fridays on WCCO Radio, 830-AM. On Twitter: @rashreport.