$100M Sub HUMILIATES U.S. Supercarrier

A $100 million diesel submarine repeatedly “killed” a U.S. supercarrier in a Navy wargame—exposing a vulnerability America can’t afford to ignore in an era of tight budgets and rising threats.

Quick Take

U.S.-Swedish exercises off San Diego in 2005 let Sweden’s HSwMS Gotland penetrate a carrier strike group and score multiple simulated torpedo “kills” on USS Ronald Reagan.
Gotland’s Stirling air-independent propulsion (AIP) and low acoustic signature highlighted how quiet conventional submarines can complicate U.S. anti-submarine warfare.
Exercise conditions mattered: reported rules and a training posture (including periods with a stationary carrier) may have made the “sinkings” easier than real combat.
The episode is still cited in 2025–2026 debates about the “cost curve” problem—cheap platforms threatening extremely expensive ones.

What the 2005 Gotland Exercise Actually Demonstrated

U.S. Navy war games in 2005, conducted off the coast near San Diego, paired a U.S. carrier strike group with the Swedish diesel-electric submarine HSwMS Gotland as an opposing-force attacker. Reporting across multiple outlets says Gotland slipped through the screen and achieved repeated simulated torpedo attacks on the aircraft carrier USS Ronald Reagan. The point was not that a carrier is “obsolete,” but that detection assumptions built for nuclear submarines can break down against quiet AIP diesel boats.

Gotland’s advantage came from design choices built for stealth in coastal waters: a low acoustic signature, hydrodynamic shaping, and a Stirling AIP system that can keep a submarine submerged for extended periods compared with traditional diesel boats. In the littorals, where background noise, temperature layers, and clutter can complicate sonar returns, the carrier group’s own activity can mask contacts. The exercise storyline, as described in coverage, underscored how a smaller navy can field a “good enough” platform that stresses big-deck defenses.

Why the “Cost Curve” Narrative Resonates With Voters

Several accounts framed the incident as a stark mismatch: a roughly $100 million submarine threatening a carrier that costs billions. Those price tags vary by source and by what is being counted—hull cost versus program cost—so readers should treat the headline numbers as illustrative rather than exact. The broader lesson, though, is simple: Washington can spend enormous sums on exquisite platforms, yet still face asymmetric tactics that don’t require matching U.S. budgets dollar for dollar to create real risk in wartime.

That reality lands differently after years of public frustration over spending priorities and “everything but readiness” politics. When government grows and money gets pushed into fashionable agendas, the defense industrial base and training pipelines still have to do the hard work of deterring China, Russia, and other adversaries. The Gotland story persists because it highlights a national-security version of what taxpayers already sense: efficiency and competence matter, and expensive systems must prove survivability under realistic conditions—not just PowerPoint assumptions.

Exercise Limits: Important Context the Headlines Often Skip

Some analysis cautions that the wargame environment likely amplified Gotland’s success. Accounts note the carrier was not always operating at full wartime tempo and that exercise rules of engagement limited how aggressively the strike group could prosecute a submarine contact. Training is supposed to reveal gaps, but constraints can also distort how repeatable an outcome would be if both sides were fighting without guardrails. Even with those caveats, the Navy still learned that modern diesel-AIP submarines deserve serious respect.

What Changed Afterward—and What Still Needs Attention

Coverage indicates the U.S. Navy treated the Gotland experience as a practical wake-up call, refining tactics and training against quiet conventional submarines. Longer-term discussion has pointed toward better sensors, improved coordination among surface ships, aircraft, helicopters, and attack submarines, and greater attention to contested littoral environments. The underlying issue remains: carriers project power, but they also concentrate value. Protecting them requires constant adaptation because the threat is evolving faster than procurement cycles.

Sweden, for its part, kept the Gotland-class relevant through upgrades and continues operating the boats as its security posture tightens in Northern Europe. With Sweden now tied into NATO’s planning, the U.S. and allies have more opportunities to learn from partners who specialize in exactly the kind of coastal undersea fight that can ambush a larger fleet. The safest takeaway is not alarmism, but realism: deterrence depends on confronting uncomfortable lessons before an enemy forces them on us.