Pentagon announces plan to expand nuclear arsenal in face of Russian threat

The Pentagon plans to develop two "low-yield" nuclear warheads to be launched from ballistic-missile submarines and warships, to send a message to Moscow -- which the Trump administration accuses of amassing a stockpile of tactical nuclear weapons. The new plan is outlined in Defense Secretary Jim Mattis's Nuclear Posture Review, released Friday afternoon. "Expanding U.S. tailored response options will raise the nuclear threshold and help ensure that potential adversaries perceive no possible advantage in limited nuclear escalation, making nuclear weapons employment less likely," the new review said.