How sabotage and disorder threaten the fragile network of undersea cables and pipelines that makes modern life possible—and how it may already be drawing the world into an all-out underwater war.

The world depends on a tangle of underwater tubes on the ocean floor. Every day undersea cables transmit 99 percent of the world’s data, while intercontinental pipelines convey two-thirds of the world’s oil and gas. They do their jobs so reliably that few would guess that “the cloud” is actually underwater, or that global economic stability relies on pipelines on the seafloor. But as award-winning security expert Elisabeth Braw reveals, an invisible battle over those cables and pipelines is ramping up.

Undersea War tells the story of the underwater infrastructure that supports everyday life. In 2022, after decades of undersea harmony, two pipelines in the Baltic Sea exploded mysteriously. Within months, the cutting of the data links between Taiwan’s Matsu Islands’ data links and the world along with the subsequent destruction of additional Baltic pipelines and cables signaled that peace in the ocean depths was over. Superpowers are now racing to protect themselves as the seabed itself becomes a battlefield.

Blending engrossing historical narrative with acute strategic analysis, Undersea War shows that the next major battle for global supremacy may unfold on the ocean floor.