Who has the authority to launch a nuclear strike?

I believe it’s the president along with a member of the executive branch that has been confirmed by congress.

Wikipedia explains:

Before the order can be processed by the military, the President must be positively identified using a special code issued on a plastic card, nicknamed the “biscuit”. The United States has a two-man rule in place, and while only the President can order the release of nuclear weapons, the order must be confirmed by the Secretary of Defense. Once all the codes have been verified, the military would issue attack orders to the proper units. These orders are given and then re-verified for authenticity.

ROFL By the time you got all the pieces in place for a counter attack we would be gone.

Hehe, biscuit.

Actually with protocols such as MAD, it’s automatic retaliation more or less, can’t sit around and debate with the “morals” and “ethics” of whether or not to fire back when the end of the world is in a few minutes!

@robmandu I think your wik answer might be wrong. I’ll look a little farther, but I don’t think it’s just the Sec. of Defense.

I am a big cold war buff and have looked in to this. While Wikipedia sometimes takes “liberties” with accuracy, the article regarding this is correct. In the US the authority to launch nuclear weapons rests with the National Command Authority, defined as ” The President and Secretary of Defense or their duly appointed successors.” Once the two of them concur, the order would most likely be carried out.

It’s not just the Sec of Defense.
http://wiki.answers.com/Q/Who_has_authority_to_launch_nuclear_weapons

Wikipedia is not the only site that says this. You can also look on sites like Global Security and Federation of american scientists. both sites talk about stuff like this. The wikianswers says that an administration official approved by congress has to also concur. The Secretary of Defense fits both criteria. He/She is an administration official. They were also nominated by the president and confirmed in the Senate which is what is necessary to assume that post.
Once these two concur the order is considered valid. The order is then passed down through the chain of command until it gets to those who actually “push the button” I.e, the sub captains, and the bomber and missile crews. This also pertains to tactical nukes in Europe.