Worrying. Of all countries, the US with its unparalleled conventional military power should need nukes less than any other country.

Nah. If we forgo nukes then you'd see the whole world scrambling to build nukes to protect themselves and our conventional advantage would get nullified. We need them more than other nations do.

But you only need them to counter nukes. There's absolutely no need for the US to be the first to stoop to nukes.

We need the posturing, it helps us to not actually have to use them.

Think about it this way. In a gang, typically the strongest and most capable warrior will be the leader. That leader has to be perfectly willing to instill fear in the others and sacrifice one for the harmony of the group if he has to. If he were to tie his own hands behind his back out of some strange sense of fairness, then he's essentially abdicating his role as leader.

The US is heavily invested in peace. We want peace more than just about every nation on the planet. By that I mean we don't just want national security, i.e. no other nations threatening us. We want every nation to be secure, happy, and open for business. We don't want random African nations fighting a war against each other. That's bad for business. France doesn't care if the Congo and Tanzania are fighting an all-out war. We do. So we invest a lot of money in institution-building at the international level.

Organizations like the African Union promote economic peace and unity but it's only possible for them to flourish if the constituent nations feel militarily secure. This is where the US's overwhelming military and nuclear dominance come into play. We have to keep our big stick, ready at hand to Hulk smash anything threatening us, so that everyone else can relax and let the cooler heads prevail.