If you have a lot of robust cheap missles, mobile or in very hardened silos, each with a low accuracy city buster, it's hard for a first strike to take them all out. And only a few need survive a first strike to punish your aggressor. So that's the way to go for deterrence. If you have a few delicate, expensive, highly accurate multiple warhead missiles in hand-me-down (already known to the enemy) silos, it is clear that you plan to go first, because your warheads are vulnerable to sneak attack and you plan to overwhelm enemy defences with a flurry of projectiles before they can react.

Remember, first strike suggests you maximize warheads (to do as much initial damage as possible) with as few launches as possible (to make their detection systems hesitate while you knock out their deterrence). Don't believe all that propaganda about how wonderful we were and how terrible the Soviets were. Both sides played dirty and both lied about it.

This later became the philosophy behind Star Wars, where we threatened to break the anti-ABM treaty we had forced the Russians to sign in the first place so we could put their economy under pressure. We won the cold war by threatening to make it a hot one. I'm convinced only Soviet restraint (and maybe cowardice) got us out of the 80s alive.

Now I don't think the USA really wanted to start a nuclear war, or conquer the world. But I do know that any military policy which maximized weapons investment was going to have advantages getting government and industry support and appropriations and would handily defeat alternative strategies. Our defense policy just naturally followed the path of maximum profit for the defense industry. It was the path of least resistance.

You simply don't know what you're talking about, Lee, I personally worked on systems specifically designed to frustrate Russian second-strike deterrence weapons which were no immediate strategic threat to us (as opposed to deterring them by targeting their cities). The stated and official doctrine in US Military policy was that by forcing the Soviets to prepare for a US first strike we could overwhelm their economy. Read "On Thermonuclear War" and "Thinking the Unthinkable" by Kahn. Of course, that's not what the government told the public. Everything WE did was purely defensive. Right