Avoiding homework.
I have a fire extinguisher in my apartment. I haven’t used it in the longest time. Maybe I don’t need…
Hah. I have several in my house that I’ve never used. My extinguisher arsenal is much larger than yours. You need to back off on your aggression.
Displacing hurricanes? Nah.
When you join the Nuclear Nations Club, you get a really cool club shirt. And don’t ask about the official secret handshake.
An air burst nuclear fusion device produces very little lingering radiation. The 1996 comprehensive test ban treaty prohibits any nuclear test detonation, underground or not – but that treaty has never been ratified nor enacted: The Status of the Comprehensive Test Ban Treaty: Signatories and Ratifiers | Arms Control Association It also has other limitations (see below).
A nuclear-powered Orion launch vehicle using optimized fusion devices could possibly lift huge amounts of payload to space without leaving major fallout.
There have been 2,153 nuclear weapons detonated on earth, or vicinity. Of these about 520 were atmospheric tests, not underground.
Numerically most of the 2,153 detonations were underground, but these were all quite small. In terms of megatonnage, about 85% of all nuclear weapon power was detonated within the atmosphere, since the atmospheric tests on average were much larger: Nuclear weapons testing - Wikipedia
This video graphically shows the location, year and type of each known nuclear detonation:
Re the OP, the only practical method of deflecting a near earth object on short notice is a stand-off nuclear detonation: An Innovative Solution to NASA's NEO Impact Threat Mitigation Grand Challenge and Flight Validation Mission Architecture Development - NASA Technical Reports Server (NTRS)
The 1996 Comprehensive Test Ban Treaty (even if it were enacted) would apparently not govern use of nuclear weapons in this way. It only bans a nation from detonating those weapons “at any place under its jurisdiction or control”. Outer space is not under the jurisdiction of any nation.
The 1967 Outer Space Treaty prohibits “stationing” nuclear weapons in space, such as in orbit. However it does not prohibit nuclear weapons transiting through space (e.g, ICBM) or detonating them in space: Outer Space Treaty - Wikipedia
Well, it might well have prevented World War III, so that’s a nice thing.
To date, anyway. It’s not like it’s off the table forever.
Basically nuclear weapons makes it so that your opponents never want to leave you in a position where you have nothing else to lose.
This is the main reason Iran wants them and North Korea got them. Iran doesn’t want to nuke Israel, they want them so that it the US will be forced to take the option of military regime change off the table.
Speak softly and carry a big stick. Nukes are tools of diplomacy. Countries with nukes sit at the grown up table at international talks, while nuke-free countries sit at the kids table and basically get told what to do.
Like the German battleship Tirpitz, which operated as “a Fleet in being,” strategic weapons can certainly fulfill a mission without being used.
We must not allow a fire extinguisher gap!
Yes, and we all know what happened to Tirpitz, don’t we! 
Sometimes nuking them from orbit is the only way to be sure.
Your nation is defended by nuclear deterrence EVERY. SINGLE. DAY.
I’m sorry, but this statement is just astonishingly ignorant. The US invested vast sums in developing a credible and indestructible nuclear capability precisely so that they would never need to use them. The West’s nuclear arsenal has successfully prevented not only nuclear war, but also major conventional wars, for the last seventy-one years.
Ever notice how we never fought a war with Russia? And ever notice how our wars have been getting progressively smaller? Notice how we’ve been fighting bullshit proxy wars in third world countries, instead of catastrophic global wars that kill tens of millions of people?
That is the DIRECT result of nuclear weapons. You’re welcome.
I recommend reading the excellent book Command and Control: Nuclear Weapons, the Damascus Accident, and the Illusion of Safety, by Eric Schlosser.
The book uses the events surrounding a Titan II missile explosion (the rocket exploded, not its warhead) in Arkansas in the early 80s as a backdrop for a very in-depth history of many of the factors involved in nuclear weapons.
As an example, at first glance, it seems outrageous and asinine that SAC missiles had their control codes set to 000000, to the point of disbelief. But after reading about the infighting between the various parties (Joint Chiefs, Sandia, Livermore, President, Congress) it is easier to see that some demanded absolute safety, while others (with uniforms) demanded that nothing get between the military and their weapons. Hence the military’s decision to undermine the safety feature, while complying to the letter of the law.
The book is chock full of stuff like that, giving lots of detail behind dozens and dozens of accidents with nuclear weapons, discussion of the concern for preventing a decapitation attack (offshore missiles targeting leadership in Washington), as well as a lot of detail about the hemming and hawing about how to design a comprehensive war plan that would involve all services, and minimize duplication, while ensuring target destruction.
As the arguments unfold, one can understand–if not agree with–ideas such as all-or-none destruction and the inability to destroy or recall missiles once they have been launched.
And yes, the author does cover the purpose of nuclear weapons.
Since someone beat me to the fire extinguisher gap joke …
The purpose of nuclear weapons in 1944 -45 was clear. To end the war and to beat the Germans. IIRC it is laid out in Einstein’s letter.
Once that happened, it was out of the bag. We certainly couldn’t trust Stalin to eschew them back then, so MAD, however insane it is, was the best option. And it worked.
I remember the Cuban Missile Crisis. Our you can listen to Dylan songs from 1963. Anyone saying that 50 years later the threat of an all-out nuclear war would be lower, and no weapon would ever be detonated in anger, would have been considered a naive optimist. But look where we are. Doomsday comes from aliens or asteroids or zombies, not from nuclear war.
No one has fallout shelters and my kids didn’t have to practice putting their head between their legs and kissing their ass goodbye like I did. We’ve actually done a pretty good job.
OP: What’s the peaceful use of an anti-personnel mine?
Well yes, but Teller was… how to say this politely… stark raving nuts and never met a thermonuclear explosion he didn’t love
The OP sort of dodges around this already, though, by saying “you can use chemical explosives in mining.” So any munition can be alleged to have a peaceful purpose in the sense that at its heart is an explosive, and explosives have peaceful commercial uses, even if the munition is quite obviously solely for war, such as an anti personnel mine, or a guided missile, or an artillery shell.
Of course, anyone can then immediately point out that the same analogy applies to nuclear weapons, since at their heart is fissionable material, which can be used for peaceful purposes, and in fact is - generating electricity.