Obama sets new nuke policy

Pres. Barack Obama announced a new policy that would limit the use of nuclear weapons by the United States, and also set new restrictions on the building of new weapons.

The announcement comes as the president prepares to visit Prague to sign a new nuclear arms agreement with Russia.

Obama's new policy would limit the use of nuclear weapons only to countries that possess nuclear weapons themselves, or that are in violation of the non-proliferation treaty. Also any nation that attacked the U.S. in a massive way might be subject to a nuclear attack.

The move is Obama's latest in his stated policy of working toward a nuke-free world.