By Dan Goure
For more than a decade, inadequate defense budgets and a high operational tempo have forced the U.S. military to shortchange modernization in order to preserve force structure and near-term readiness. Even when a service initiates a new major acquisition program such as the Air Force’s F-35 fighter, B-21 bomber and KC-46 tanker, the numbers that will be procured each year are relatively small. This means that the military will be required to operate older platforms for years and even decades longer than planned. These older systems require more maintenance and upgrades to critical systems, which drain the resources available for modernization.
Nowhere is the problem more challenging than in the Navy’s submarine force. The Navy operates two different fleets of submarines. One is the nuclear-powered ballistic missile submarines (SSBNs) that constitute a leg of the nuclear triad. There are 18 Ohio-class SSBNs, 14 of which carry Trident sea-launched ballistic missiles and four that were converted to employ sea-launched Tomahawk cruise missiles and are officially designated as guided-missile submarines, or SSGNs
http://nationalinterest.org/blog/the-buzz/the-us-navy-needs-build-more-nuclear-attack-submarines-22501
