This Is How the U.S. Navy’s Submarine Force Dominates the World’s Oceans

Though Russia continues to develop and build newer and ever more capable nuclear attack submarines such as the Project 885M Yasen-class, the U.S. Navy continues to maintain its technological edge by incrementally improving its Virginia-class attack boats.

http://nationalinterest.org/blog/the-buzz/how-the-us-navys-submarine-force-dominates-the-worlds-oceans-16243