On Oct. 7, Russian warships in the Caspian Sea fired 26 high-tech cruise missiles at rebel targets in Syria—a staggering 1,000 miles away. The missiles in question, which the Pentagon calls SS-N-30s, were mostly unknown to the outside world before the Oct. 7 raid. Even close watchers of the Russian military were surprised to see them. The missile attack was also highly visible. In many ways, it was an announcement to the world, and America in particular, that the once-dilapidated Russian navy is back in action—and that Putin’s missileers are now among the planet’s most advanced. Planning for the missile...