There were five Marines and one Navy Corpsman photographed raising the U.S. flag on Mt. Suribachi by Joe Rosenthal on February 23, 1945. This is the story of three of the six surviving servicemen - John 'Doc' Bradley, Pvt. Rene Gagnon and Pvt. Ira Hayes - who fought in the battle to take Iwo Jima from the Japanese.
The concept of 'collective memory' refers to the joint recollection of the past by a nation, a community, or additional groups with elements of a joint identity. The underlying assumption is that peoples' memories are shaped not just through their own individual experiences, but also through social processes and shared imagery. The film gets one thing right about the 'actual' details of the events that comprise our collective memory: the facts don't actually matter. Indeed, humans appear to be highly resistant to factual debunking in general — just look at the woefully effectual fact-checking that attends Donald Trump.
So despite learning that the photo was 'actually' a second flag (and was taken on only the fifth day of a 40-day battle), the film is helpless when placed against what we feel we know about the war, and it therefore fails at its explicit promise articulated in its opening narration: that is, to dismantle the usual binary between 'heroes' and 'baddies' of soldiers in war. However, it declines to follow through on this (admittedly impossible) task, and can rise only to depict the Marines as conflicted heroes suffering from guilt and PTSD.
Susan Sontag touched on the curious relationship between famous war photographs and the medium of cinema in her book-length essay, Regarding the Pain of Others (2003):
What is odd is not that so many of the iconic news photos of the past, including some of the best-remembered pictures from the Second World War, appear to have been staged. It is that we are surprised to learn they were staged, and always disappointed. [And] with time, many staged photographs turn back into historical evidence, albeit of an impure kind—like most historical evidence. [Furthermore,] what assured the authenticity of Steven Spielberg’s acclaimed re-creation of the Omaha Beach landing on D-Day in Saving Private Ryan (1998) was that it was based, among other sources, on the photographs taken with immense bravery by Robert Capa during the landing. But a war photograph [now] seems inauthentic, even though there is nothing staged about it, when it looks like a still from a movie.
It is noteworthy that the Japanese are hardly depicted in this film at all: the most profound engagement with the enemy in Flags of Our Fathers is through photographs of war crimes committed by the Imperial Japanese Army. A war film has no strict responsibility to humanise the enemy, of course, but it is another thing to go the additional step of dehumanising them. Moreover, the sobering use of atrocity images actually masks that the film is creating a new binary of its own, specifically between the noble-yet-complicated photograph of Marines raising the U. S. flag versus the wicked-and-monstrous images of 'the Japs' cutting off the heads of prisoners of war.
Indeed, the real bad guys in Flags of Our Fathers are actually the politicians and the military, who are depicted as being vulgarly obsessed with public opinion insofar it will help sell savings bonds to 'pay for the war'. Very Clint Eastwood, now that I think of it. But instead of a thinking man's Saving Private Ryan (1998) set in the 'forgotten' Pacific theatre, we get an Eastwood-inflected 'War Bond of Brothers'. What is more, the film's suggestion that it was a passing and off-hand idea to place Ol' Glory at the top of Mount Suribachi is highly convenient to the film's overall message; namely that the good ol' US Marines would never steep to any kind of crass PR exercise. But this is undermined by the reverence the Marines — and the film itself — has for the flag itself.
From a technical perspective, the over-reliance on CGI hasn't aged especially well in the last two decades, and the term 'colour correction' is a strange euphemism when applied to this movie — the flashbacks from 1945 are so desaturated it's less colour correction than colour confiscation. Still, the artistic choice still feels somewhat justified given the ghostly quality of the soldier's memories combined with the morally grey philosophy depicted throughout. And from a narrative point of view, the double framing device (that is, of a son writing the book that this film is itself based on) is decidedly ill-executed, adding a clumsy 30-minute coda to a film whose message we grasped within the first hour or so.
Casting and performances are mixed. On the one hand, the year after the release of this movie, silver fox John Slattery would reprise his role as the crass and avaricious id of America in AMC's Mad Men (2007—2015). Yet apart from Adam Beach's portrayal of Corporal Ira Hayes, the rest of the soldiers are essentially interchangeable. Indeed, Dana Stevens of Slate makes a good point on this:
Flags relies too often on the standard war-movie structure: Develop the soldiers’ characters just long enough to be able to tell them apart, then throw them on the battlefield to be picked off, one by one, in increasingly horrible ways. […] It feels disrespectful to say it, but this kind of war movie, like war itself, is starting to feel sickeningly familiar.
This is a messier, more ambiguous picture than we'd expect of Eastwood, and it's not always easy sledding: The structure is somewhat fragmented and confusing, and Eastwood can't resist throwing in some corny, macho-sentimental voice-overs. There are many places where Eastwood's technique and sensibility jostle each other like roughhousing, squabbling brothers: There will be a shot, or a whole scene, that shows us he's followed some gut instinct -- the best moments in Flags of Our Fathers are effective because of, not in spite of, their blunt simplicity. But Eastwood doesn't know when to stop: He'll expand upon and explicate a point until he grinds it down, diminishing the power of ideas he's already conveyed quite effectively. He'll give us a clear set of dots to connect and then, as if he doesn't trust us, grab the pencil and connect them himself. And sometimes, the movie is just plain boring.
— Stephanie Zacharek (Salon)