Four Cables Down At Once, 30% of the Country's Bandwidth
In late August 2026, Vietnam's international internet connectivity took its worst hit in years. The SJC2 and AAE-1 submarine cables suffered faults almost simultaneously around August 25 — SJC2 on its S4 segment near Chung Hom Kok in Hong Kong, AAE-1 on its S1.H2 segment — on top of pre-existing faults on AAG and the Tata TGN Intra-Asia (IA) system. Four of the eight cable systems serving the country were down at once, knocking out roughly 30% of Vietnam's international internet capacity (Light Reading; VietNamNet). AAE-1 had, in fact, never fully recovered from a separate fault in February 2026 that cut roughly 3,700 Gbps of capacity during Tet (baochinhphu.vn). Repairs on TGN-IA were slated to begin in early September; no timeline has been announced for the other three (VnExpress).
What makes this outage notable isn't the failure — Vietnam's cables fault with grim regularity, landing as they do in a seismically and commercially busy stretch of the South China Sea where repair ships queue for months. What's notable is what didn't happen: no mass outage, no emergency data-localization order, no throttling mandate. VNPT rerouted traffic and Viettel added roughly 800 Gbit/s via the IA cable and 300 Gbit/s via APG, while pushing an extra 1.5 Tbit/s onto the Vietnam-Singapore Terrestrial Network — a 3,900km overland fiber route through Laos, Thailand and Malaysia that Vietnam only switched on in 2025 (Light Reading).
A Strategy That Was Already Written Down
That the Laos route existed at all to absorb the shock traces back to Decision 1132/QĐ-TTg, the Digital Infrastructure Strategy the Prime Minister's office approved on October 9, 2024. It set a concrete target: at least six new submarine cables online by 2030, taking Vietnam's design capacity to a minimum of 350 Tbps, plus at least one cable Vietnam itself owns and operates end to end, and at least one international terrestrial route (baochinhphu.vn). The strategy also codified a "1+2" redundancy rule — usable capacity should run at three times actual demand — which is precisely the buffer that let VNPT and Viettel absorb a 30% capacity loss without visible service degradation for most users.
The Case for Planning This Kind of Infrastructure
It's worth stating the strongest version of the pro-intervention case plainly, because it holds up: no single private carrier has the incentive to build a 3,900km backup route through three foreign countries on its own. Repair vessels for subsea cables are scarce and shared across the whole Asia-Pacific region — fixes routinely take two to twelve months, and a carrier whose cable is fine has little reason to subsidize a competitor's redundancy. Left purely to individual operators, Vietnam would likely have kept adding subsea capacity in the same congested corridors while remaining structurally exposed to the exact failure mode that just occurred. A national resilience target that forces operators toward genuine route diversity — sea and land, multiple landing countries — solves a coordination problem that the market, on its own, has shown no urgency to solve.
Where the Model Could Tip Into Overreach
The proportionality test is what happens next. The VSTN route is built and operated entirely by VNPT, and Viettel — Vietnam's two largest, state-owned telecom groups — control both the incumbent subsea capacity and the new overland alternative. That's a defensible outcome of an emergency-response strategy, but it concentrates chokepoint control in the same two state hands rather than diversifying it across independent operators. If Vietnam's 2030 target of 15 total cable systems is met mostly by VNPT- and Viettel-led consortia, the country will have addressed route diversity while leaving ownership diversity largely untouched — a distinction that matters if the resilience narrative is ever repurposed to justify traffic-inspection or data-localization requirements on "national security" grounds. So far, MIC's response has stayed narrowly infrastructural: capacity targets, timelines, and redundancy ratios, not new content or routing mandates. That restraint is the part worth crediting, and the part worth watching closely if it slips.
What to Watch
- Whether SJC2, AAE-1 and AAG get repair dates — undersea repair backlogs across the region are the real capacity constraint, not policy.
- Whether the 2030 target of 350 Tbps and 15 systems keeps pace; faults are currently outrunning the buildout.
- Whether new cable consortia genuinely diversify ownership beyond VNPT and Viettel, or whether Vietnam's redundancy remains two state carriers running parallel infrastructure.
Vietnam's approach — publish a capacity target, mandate a 3x redundancy buffer, let carriers build to it, and let a state-directed backup absorb the gap the market wouldn't fill alone — is proportionate infrastructure policy done reasonably well. It's a model other Southeast Asian states with similar cable exposure should study, provided Vietnam itself doesn't let a resilience mandate quietly widen into a control mandate.