These Chinese nuclear submarines show it's serious about countering US dominance under the waves

• China has built upon decades of earlier failures to field a growing submarine force.
• Its attack boats and boomers have grown much quieter and harder to track.
• The fleet build-up shows the importance China believes subs will have in future conflicts.

Two days before US Secretary of State Antony Blinken arrived in China this April for meetings with the country's leader and other high-ranking Chinese officials, China's People's Liberation Army Navy released footage of a nuclear submarine firing a ballistic missile.