Prompt Global Strike replaces previous nuclear-based alternatives
The need for a large nuclear stockpile and a first strike capabiltiy is being replaced by the Prompt Global Strike initiative.
Background on Prompt Global Strike from
Wikipedia:
"Prompt Global Strike (PGS) is a United States military initiative to develop a system capable of a conventional weapon strike anywhere in the world in 1 hour, just as a nuclear attack can currently be carried with intercontinental ballistic missiles.
As stated by General James Cartwright, "Today, unless you want to go nuclear, it's measured in days, maybe weeks" until the military can launch an attack with regular forces. The aim of the system is to provide rapid precision strike capability to any region in the world in case of a conflict or emergency.
The ballistic version would be launched from the United States mainland . The PGS system will be designed to complement Forward Deployed Forces, Air Expeditionary Forces (which can deploy within 48 hours) and Carrier battle groups (which can respond within 96 hours) with a system that can deliver a strike anywhere on the planet or in near space within 60 minutes."