It's official. K-560 Severodvinsk, Moscow's newest and most advanced nuclear attack submarine, has joined the Russian navy.

That's bad news for most countries that could conceivably face Russia in a conflict. The expensive, quiet, 13,800-ton Yasen-class submarine is arguably one of the most sophisticated in the world — and she's just the first of her class.

But the one country that doesn't have much reason to worry is the United States, which has a significantly larger and more modern submarine force.

The Yasen class is also an exception to the rule in Russia, where most warships are obsolete or severely compromised by poor maintenance and training.

Russia took its time on the Yasen program. The project dates to the Cold War, as the Soviet Union planned a submarine that could hunt U.S. Nimitz-class supercarriers and also escort the USSR's larger, nuclear weapon-carrying submarines within range of American cities.

This necessitated a submarine that was faster, quieter, and deadlier than existing Akula and Sierra-class attack subs.

Then-president Dmitry Medvedev next to Severodvinsk in 2010. (Photo via Wikipedia, courtesy War is Boring)

Russia begun building Severodvinsk way back in 1993. The post-Soviet economic collapse forced the Kremlin to delay the program. But despite being years late, she's still one of the most advanced submarines in the world.

She's nuclear powered, for one. She has a more powerful sonar system, including a big sonar array mounted in the bow. The vessel also packs an impressive arsenal of torpedoes and 24 anti-ship cruise missiles of the Oniksand Kalibr types.

But while Severodvinsk is individually dangerous, a single submarine — or only a few — isn't enough to defeat the U.S. Navy. The entire Yasen class is also expensive. It's unclear exactly how much each one costs. Estimates range from $1 billion to $3 billion.

Back in the 1990s, the Russians wanted to build 30 of the class. The number has fluctuated since then and now the goal is nine, including Severodvinsk. Two of the class, Kazan and Novosibirsk, are currently under construction. That's still enough to pose a serious threat to most countries Russia could conceivably come into conflict with.

But then you see the problem. This means Russia is spending more money than it needs to, to defeat potential foes other than America — and not enough to stand up against the U.S. Navy.

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