Laugh if you like, but America is taking seriously North Korean threats to "nuke" the continental United States. On Friday, newly installed Secretary of Defense Chuck Hagel held a press conference in which he outlined serious, urgent measures the Obama Administration is undertaking, just in case North Korean dictator Kim Jong-un isn't joking.

Specifically, Hagel announced that "in order to bolster our protection of the homeland and stay ahead of this threat," the U.S. is taking several steps. Chief among them, the Defense Department plans to purchase and deploy 14 additional ground-based interceptor missiles under the Missile Defense Agency's Ground-Based Midcourse Defense program.

Boeing (BA 0.06%) manages this program, in which Raytheon (RTN) AN/TPY-2 radar systems detect ballistic missile launches, which are then hit-to-killed by Raytheon warheads launched atop Orbital Science (OA)-built missiles. The U.S. currently has 30 such interceptor missiles in its arsenal. Adding 14 more is expected to cost $1 billion. Hagel confirmed that the U.S. will probably draw funds away from Raytheon's SM-3 Block IIB missile, and the European missile defense project for which it was designed, to fund improvements in missile defense on the U.S. West Coast. Other measures announced by the SecDef include purchasing and deploying an additional AN/TPY-2 radar systems to Japan.

The net effect of all these changes, says Hagel, will be "to add protection against missiles from Iran sooner while also providing additional protection against the North Korean threat."