China’s SQUID Gravity Detector Nears US Nuclear Submarine Tracking

China’s breakthrough SQUID gravity detector threatens to upend submarine stealth by targeting US nuclear fleets. The sensor’s unprecedented precision could shift underwater warfare dynamics in the Indo-Pacific, escalating great-power military competition.

Chinese researchers last month unveiled a gravity detector using a superconducting quantum interference device (SQUID) that achieves world-leading sensitivity. This breakthrough allows the detection of minute gravity fluctuations with unprecedented accuracy.

SQUID technology operates by sensing subtle changes in gravitational fields, enabling the potential identification of concealed or submerged objects, such as underground resources or submarines. The Chinese team claims dual-use applications, blending scientific inquiry with military reconnaissance.

The strategic fallout is profound: if China's gravity sensors are integrated into naval reconnaissance networks, they could detect and track US nuclear ballistic missile submarines (SSBNs), undermining a critical pillar of US nuclear deterrence. This could trigger shifts in anti-submarine warfare tactics and force postures across the Indo-Pacific.

The device’s technical specs remain classified, but SQUID sensors typically require cryogenic cooling and deploy superconducting circuits sensitive to changes smaller than the gravitational influence of a parked vehicle. Such sensitivity enables detection of submerged submarines generating minute gravity anomalies.

Moving forward, Beijing may accelerate the weaponization of SQUID technology to overcome stealth in undersea domains, pushing rivals to respond with new countermeasures. This sparks a dangerous undersea detection race with escalated surveillance, potentially destabilizing strategic stability in contested waters.