In a hypothetical situation, one country pissed off enough people that nuclear bombs are now an option. A few countries have launched nukes at the one country. There is seemingly no hope for survival, however:

You are the leader of the doomed country. Do you launch nukes back and cause mass destruction, or do you accept your death and allow your country to be the only casualty? You could fire back, and maybe scrape away, but most of the Earth would become uninhabitable. If you don't fire, your country would be destroyed, and the remaining countries that launched the nukes would become the aggressive, undisputed rulers of the rest of the world; however, most of the Earth and human population wouldn't be harmed by the initial conflict.

Of course, in a real situation the entire world would be fucked and everyone would be firing nukes at everything, but just work with the hypothetical.

AAAAAYYYYYYYYYY

become an hero

Stay my hand. A big fuck you bang up party is pretty tempting. But in surrender and acceptance, you gain a far bigger fuck you.

1. All of histories villains? The people we hated, feared, detested, and everything else? They're all dead. Their empires, are dead. The point is, times change. So even if the country that was the last man standing, the dirty little fucker who started it all was left, times would change. Everything rises, everything falls.

2. Nukes are fast. But not instant. They probably have a long enough travel time, that as the leader of your doomed country, you could broadcast a message. A farewell to all, and a call to arms. A message that says "I had the choice to fire. And I didn't, because I'm not the man on the other end of the oncoming missiles towards me." In conjunction with "everything changes," you leave a message of peace, a warning, and a call to arms to those who would fight and incite rebellion on the last man standing.

3. What's a bigger fuck you and crippling blow to your assailaint's ego then watching your oncoming death with a smile and not a care?

Bend over and kiss my ass goodbye.

ITT

I'd nuke the gay whales

How much time do I have? If I truly am the dictator then I'm sure I'dd have some fun toys to play with. Before we got nuked I'd release every deadly bio-weapon in my arsenal into their lands, then release all of the backing research to the head countries. Then I would die by the nukes gracefully.
My toys can't have fun when there's no one around or the earth is uninhabitable.

You must be fun at parties, and the apocalypse.