How and why are key Indo-Pacific states adapting respective foreign and defence policies to secure submarine cable networks amid heightened Sino-US network-based competition? States are driven to control submarine cable networks as these infrastructures transmit information between continents and islands, traverse vulnerable maritime zones, and constrict data through limited chokepoints. China's Digital Silk Road has challenged Western submarine cable dominance, prompting a suite of countermeasures by Western states individually and in coalition. This Element posits a nodes-flows-production typology to illustrate how states are attempting to control connectivity nodes, secure transmission flows and dominate production. The analysis highlights how states are pursuing central network positions to mitigate vulnerability – but this structural competition risks enabling weaponisation. This microcosm of network-based competition reveals how the contest to control submarine cable infrastructure is defining contemporary great power rivalry and re-wiring the Indo-Pacific's arteries. This title is also available as Open Access on Cambridge Core.