That's actually the best (only?) time to use them. Last ditch weapons and all that.
Do you not know what "in a pinch" means?
in a pinch
being in a situation where the preferred or ideal choice is unavailable.
appearing as a substitute.
to be hard-pressed.
to be in an emergency.
being in a terrible situation where you need help.
If you can't see why resorting to nuclear weapons when they are not the best choice is a bad idea, all I can say is we are lucky you don't get to make that decision. However I'm worried that Donald Trump might use them because
he is 'in a pinch' politically. It's just the kind of reckless self-serving thing he would do, and I'm concerned that his incompetent sycophants would go along with it - perhaps even cheer it on.
I was less worried about global nuclear war during the Cuban missile crisis than today. Back then world leaders understood the responsibility they shared, and the biggest fear was a technical glitch. Not so today. We have three world leaders who are reckless, and one of them is a narcissistic idiot who can barely read.
The age of nuclear wars won't start with an apocalypse, but with limited tactical use that escalates until everyone is doing it - just like previous weaponry did. I only hope this doesn't happen in my lifetime, preferably because humanity has grown out of such idiocy. That's why we need to keep previous idiocies like WW I and II fresh in our minds.
The US didn't drop nuclear bombs on Japan because it was 'in a pinch', the action was carefully considered and assessed to be the best option. President Truman got away with it on the premise that more civilians would die in a conventional invasion (which was true). Since then many countries have acquired nuclear weapons, but none have used them. It would be a real shame if that record of non-aggression was broken by a beleaguered President attempting to shore up cratering domestic support.