Geography has always governed geopolitical strategy, the height of mountain ranges, the depth of maritime chokepoints, and the width of sovereign borders. But as the global security landscape evolves toward a permanent existence in the grey zone, fueled by artificial intelligence, autonomous systems, and constant information flows, there is a new, invisible theatre of war: the human circadian rhythm. Illustration by The Geostrata Historically, conflict was observed at night.

Imagine a weapon that can take down a country's entire communication satellite system, completely cutting them off the global grid, or...