The Soviet Union produced hot-rod submarines that could swim faster, take more damage, and dive deeper than their American counterparts—but the U.S. Navy remained fairly confident it had the Soviet submarines outmatched because they were all extremely noisy.

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Should the superpowers clash, the quieter American subs had better odds of detecting their Soviet counterparts first, and greeting them with a homing torpedo.

However, that confidence was dented in the mid-1980s, when the Soviet Navy launched its Akula-class nuclear-powered attack submarines. Thirty years later they remain the mainstay of the Russian nuclear attack submarine fleet—and are quieter than the majority of their American counterparts. …