They don't act as a deterrent unless the enemy believes that you are going to use them. I don't think the Russians [Soviets], Chinese, North Koreans, Iranians, and Paks have the slightest doubt that we will use them. Your logic is flawed. AQ represents a different kind of threat, i.e., a non-state actor. We have weapons we can use against them. There are different threats, hence you have a range of weapons to deal with them.
Although I am an electrical engineer with no particular expertise in nuclear weapons technology, that doesn't imply that I have to check my common sense at the door.
It doesn't sound like you have any kind of sense. If you read the article, "The new weapon would not add to but replace the nation’s existing arsenal of aging warheads, with a new generation meant to be sturdier, more reliable, safer from accidental detonation and more secure from theft by terrorists."
"Both administration officials and military officers like Gen. James E. Cartwright, head of the Strategic Command, which controls the nation’s nuclear arsenal, argue that because the United States provides a nuclear umbrella for so many allies, it is critical that its stockpile be as reliable as possible.
“We will not ‘un-invent’ nuclear weapons, and we will not walk away from the world,” General Cartwright said in a recent interview. “Right now, it is not the nation’s position that zero is the answer to the size of our inventory.”
“So, if you are going to have these weapons, they should be safe, they should be able to be secured, and they should be reliable if used,” General Cartwright said in the interview, conducted before the Department of Energy’s decision was announced.
We need a nuclear arsenal and we can't allow the present one to deteriorate without replacing it. How difficult is that to understand?