India and Pakistan usually view one another over the barrel of a gun. That mutual animosity is crystallised in a ceremony that takes place every evening just outside the northern Indian city of Amritsar at Wagah, one of only two crossing points along the entire 3 310km of their shared frontier.
The event is known as Beating Retreat, the military ceremony that sees the nightly closing of the gates between the two countries and lowering of their respective flags, yet this mundane affair is an exhibition of nationalism that is not often seen off the cricket pitch.
The bus from Amritsar leaves us close to the border control post and in a crowd of turbaned Sikhs we shuffle along a path that makes a rambling foray into wheat fields. The path ends at an amphitheatre. To our left is India. The tiers of concrete stands hold 8 000 spectators, and they're filling fast.
To our right is the gate that marks the border and on the other side is Pakistan, and a similar arrangement of stands with perhaps 2 000 Pakistanis. On the Pakistan side, women are separated from men.
Keeping a watchful eye over the crowd are several troopers of India's 180 000-strong Border Security Force, and they're all excessively lofty. The BSF soldiers at Wagah are chosen for their height. Not one of them that I see stands less than 1.88cm in his white gaiters.
In the peculiar game of one-upmanship that is played out daily at Wagah, height matters. Underlining their stature, the soldiers sport what looks like a cock's comb, a pleated, fan-shaped headpiece in red and gold.
The atmosphere is taut with patriotic fervour. A group of about 50 youths marches along the roadway that crosses the border, under a banner that proclaims "World Social Forum". Then an mc appears, a tall man with a moustache, who begins working the crowd with the chant "Hindustan Zindabad" - India Forever - while the Pakistanis echo with their own refrain.
Excitement ripples though the stands and the guards struggle to maintain control. A skinny youth in a black shirt waves a big Indian flag in front of the crowd, then runs towards the gate and brandishes it at the Pakistanis, then a couple of girls grab the flag and do the same.
Now the flag passes to a man with one leg and a crutch who storms towards the gate, waving the banner furiously. The crowd goes wild.
The mc calls for calm and a squad of BSF troopers emerges from the guard house. A pair of soldiers wearing white gloves and carrying swagger sticks begin to march towards the gate in double-time, followed by the troopers.
The word "marching" requires some explanation. This is more like a charge - four men in tight formation do a full-throttle goosestep, legs pumping, arms swinging like pendulums gone mad, advancing towards the gate with a scowl of pure, unblinking hatred fixed on their faces.
The Pakistani Rangers meanwhile are doing the same thing on their side and they meet at the gate.
An Indian officer appears to shake hands with his Pakistani counterpart. Behind them is a great deal of theatrical stamping. Imagine a man trying to kick a ball suspended above his head, then slamming his foot down as hard as he can, all in unison with his opposite number.
There's also considerable shouting, grimacing and virtual head-butting as the two sides face off at close quarters, as well as a lusty display for which I can think of no military phrase other than "spitting at the enemy".
The crowd is loving this. I don't speak Hindi, but the man next to me is tugging at his friend's kurta and saying something like "See that, Rajiv? Chapatti all over that Paki wallah's uniform."
What we are seeing is thrillingly dangerous. Two nuclear-armed countries with vast armies and a deep, implacable loathing for one another, divided by history and spurred on by religious fanatics. At the one point where they intersect, the animosity is distilled and cloaked by this formalised ritual.
The flags are lowered in unison. Despite the antagonism, there is a high degree of co-ordination in the macramé that goes on between the two sides.
Eventually the flags come down with a flourish, they're furled and folded and the gates swing shut. The soldiers march back, there are more high kicks in front of the regimental emblem and a voice over the loudspeaker announces the Hindi equivalent of "show's over".
The stands are abandoned and the crowd streams away. The mood is extremely buoyant, like supporters whose team has just won a football match.
Teenagers skylark and show off, adults jostle to be photographed with soldiers and innocent tourists as they head back along Amritsar Road - which just goes to show that a boisterous display of naked aggression is wonderfully uplifting for the spirits.