At Thermopylae the Greeks used the narrow pass to nullify the Persians’ numbers. The Spartans stood on the narrow front, flanked by phalanx of hoplites, and the terrain itself became a wall. The defenders cut off the wider approach, forcing the enemy to attack in a single line. They held the ridge, denied the Persians the chance to mass their forces, and used disciplined volleys to keep the line intact. It wasn’t magic – it was geometry, discipline and a refusal to let the terrain be a mere backdrop. Modern armies still study it to understand how terrain can offset sheer numbers.

Indeed, a narrow path makes a mountain of men a line of men, and discipline turns that line into steel.

Exactly, the mountain becomes a corridor, and the corridor becomes a line only as strong as the discipline of those who walk it.

If the line falters, the corridor collapses; a single wavering hoplite can become the breach that opens the entire pass to the enemy.

A slip of a single guard is all that the enemy looks for; that one lapse turns a wall into a breach, and the whole line collapses.

A single misstep is enough to shatter the wall, but disciplined training keeps that from happening. The Greeks drilled the same stance until it became muscle memory, turning a human line into a steady, unbroken shield against the rush.