Worst Case: Pretty simply, one side or the other starts a nuclear war. Which would be the end of most life as we know it. "Tactical" nukes are not nearly as small scale as they might lead you to believe.
Best Case: There's really not a great outcome of war. That bloodshed stops immediately and people can start to rebuild.
Practically speaking: At some point in time Ukraine will have to come to the negotiating table. They could have done it a long time ago, but they didn't. The biggest question mark is what kind of terms Russia would accept at this point. Would they even believe any concessions from Ukraine after Minsk was found to be a sham? I can't speak to that, I have no idea what Russian officials are thinking, but I would be surprised if they would accept anything short of unconditional surrender. There was a time where I think they would have accepted indepencent for Donetsk and Luhansk, along with a guarantee of Ukrainian neutrality. I am not sure that is enough now.
EDIT:
Your additional question. US arms manufacturers benefit from every war, more customers. The average USian is not going to see a shred of those benefits unless you are a lockheed executive.
A nuclear war would not end life on earth. Climate change is a far, far bigger threat than any nuclear war. And tactical nukes are merely big bombs. Mariupol or Bhakmut were destroyed by conventional bombs, they're still destroyed the same.
In a full scale nuclear exchange between two countries that have enough firepower to glass the planet several times over, yes life as know it currently would be ended. No, 100% of all life would probably not be destroyed, but irrevocable damage would be done. Being concerned about climate change and not nuclear war is bizarre, do you think nuclear war wouldn't damage the climate? For those who didn't die in the initial blasts or the resulting nuclear fallout, the lasting effects of nuclear war on the climate would be staggering. I do not understand how somebody who claims to be worried about the environment can literally be advocating nuclear war.
Downplaying tactical nukes as "merely big bombs" is the most assinine take for justifying nuclear war I have ever heard. A tactical nuclear weapon is still a nuclear weapon. You are still talking massive shockwaves and radiation that will poison the surrounding environment and will absolutely have devastating effects wherever they are used. They are not conventional bombs and should not be thought of as such.
That isn't even factoring in how likely it is that one side will escalate to strategic nuclear weapons should any nuclear firepower be used. There are strategic nuclear weapons that exceed the bomb of Hiroshima by 100x in some cases. Some of which the US has stationed in NATO bases.
Japan had the infrastructure left to rebuild those cities. If a full nuclear exchange occurs, there will be no infrastructure, no healthy land for agriculture, no population to rebuild anything, there is just no possibility of recovery. I'm sorry but your take is unhinged.
True, I do enjoy reading more. Any literature you can recommend on the topic? I'm mostly relying on my understanding of nuclear famine, and the logical consequences of destroying vast amounts of infrastructure and population.
Well, I understand now why the kremlin propaganda wave the nuclear threat like that. It does work.
In the meantime it didn't take any nuke to shake the food and energy markets. A blocus in the black sea and an embargo on Russian gas was all it took. So yes, a nuclear warhead would definitely destabilise world economy. But that's more because it'd be a war in the western world.
The problem is that you're missing the specifics. A nuclear war wouldn't be the destruction of the whole world. It'd be a few countries. It wouldn't be more destabilising than covid for example. It wouldn't be more destabilising than a war in Europe or on America's soil. Would some government shatter? Yes. Would it be the end of world? No.
No country is planning on painting the world in nukes for the sake of maximum radiation and destruction coverage.
Global warming though is already starting to alter agriculture productivity and conditions of life. It m's already causing problems for food, water, disasters and rising ocean levels. If you want to be scared for an actual threat, you should look this way.
I would argue that the destruction of major productive centers would be as disastrous as climate change. Why can’t both be true?
I could also be minimizing the threat of climate change by saying that the world won’t end because of it. It is an unreasonable bar however for us to consider something to be destructive. I don’t think it’s controversial to not want millions of deaths.
Then you should see what Hiroshima and nagasaki are today. They’re more living than many places on earth.
I live in Japan asshole, I have been to both. The amount of people who died in the aftermath of the bombing more than double those killed in the initial explosions. Leukemia was one of the biggest lasting effects, which predominantly affected children. Cancer rates went up. There are still people alive (albeit very few anymore) suffering aftereffects of the bombing; including people who lived far from the blast at the time of the bombing.
Those were 15-20kt blasts and only two. There are strategic weapons in both US and Russian reserves hundreds of times more powerful than that.
I wasn't saying a bomb does't kill people. I'm saying nukes can't end humanity. That's a hard fact. Unlike global warming.
Nuclear bombs are as damaging as war can be. That's all. You're from Japan? Then how many japanese died from the war before the bombs were launched? How many people the Japanese killed before these bombs? Compare the numbers.
Statistics are cold and heartless. Radiations don't kill more than napalm, shrapnel or lead.