Just as the songs in musicals must sparkle, the jokes in comedies must land and the scares in horrors must chill, the battle scenes in war films really need to fizzle.

On that scale, Tae Guk Gi simply excels. The battles display the true horror of war – brutal, loud, disorientating. Set during the Korean War, you have the modern air strikes and heavy artillery, but also the face-to-face scraps with bayonets and knives.

Often placed in the centre of these battles in the trenches, this is a profound anti-war film simply by demonstrating the blood-stained terror of fighting in one.

There is also an emotional depth and development of characters here, as we encounter how cobbler Lee Jin-tae (Jang Dong-gun – Nowhere to Hide, Friend) and his younger brother Jin-seok (Won Bin – Mother, The Man from Nowhere) transition from close siblings in Seoul to distance soldiers at war.

While Jin-tae is chasing his shoe shop dream, Jin-seok is the family’s bright spark and is continuing his education when war breaks out between North and South Korea in June of 1950.

Jin-seok is rounded up and forced onto a train heading straight to the front line of the war. As Jin-tae attempts to haul his little brother off the carriage, he finds himself on route to war too, breaking the protocol of just one man being taken from the same family.

When they arrive, Jin-tae continues to make attempts to protect his brother, volunteering for dangerous missions on the promise that a bravery medal will facilitate Jin-seok’s transportation back home to the family.

There are plenty of real-life examples of how the horrors of war change people. Here we see the moral compasses of these two brothers start to spin in other directions. While Jin-seok sees this being about both their survival, Jin-tae at first aims to save his brother, but soon gets wrapped up in the fame and praise of being a war hero.

While those epic battle scenes leave you rattled, there are vast degrees of classic Korean cinema melodrama which often feel especially jarring in the context of the surrounding war horrors. The performances are too often hammy and exaggerated, holding back the film in parts.

That is not to say it fails to pull your emotional heartstrings. While the other soldiers are there alone, we see the pain and fear of losing a sibling in battle with the Lee brothers. The panic in the seconds after a shell drops, doubled as they look round to see if their brother has survived too.

Tae Guk Gi (also written as Taegukgi on occasion) might be one of the most immersive war films ever made. It is us in the trenches too, looking skyward as the planes fly over or spinning around to see where a bullet will flash from next. A fine piece of war film craft.