Being able to intercept incoming strikes, and cripple those firing the missles is by far the biggest advantage we could have if another country decided to use the weapons. That is why it is important for the U.S. to continue to push the advancement of military technology.
They say it would only take around 400 nuclear strikes in order to kill the world. Imo this is the biggest reason Russia is so against NATO. It makes the Threat of Russia using nuclear weapons almost completely muted as almost all of their functioning nuclear weapons would be destroyed before leave Russian air space. It's believed that Russia has 11 or so nuclear capable submarines.
China is a much bigger threat already on the world stage compared to Russia. Even though they have fewer nuclear missles, the likely hood of them being able to deliver a strike is far greater. With China pushing for fast expansion of their submarine fleet over the next few decades.
With countries like Iran and North Korea, what makes them dangerous is they are much more likely to not bother to weigh the cost to the world and use their weapons regardless of the outcome. This is why securing our allies in the Asian pacific is extremely vital to our own national security in the US.
Correct on missile defence. However, the rest is, how to put this politely, completely mistaken. During the height of the cold war, there were over 400 nuclear devices targeted on Moscow and Leningrad alone, those two cities would be glowing quite nicely in the dark but the test of the world will be just fine. Even the entire cold war arsenal of around 70,000 nukes wouldn't be enough to kill the world or even humans, billions would die but it wouldn't be an extinction event for us.
As for Russia, the reason they're against NATO is because of missile transit times to Moscow & St. Petersburg. With the old Warsaw Pact boundaries they had around 20-30 minutes to deal with a NATO missile strike on either city which gives enough decision making time to either respond with a tactical nuclear strike or a full out strategic strike if that's what needed. Moving the borders all the way up to Russia proper reduces that response time to only 5-10 minutes at best, which means any missile launch towards Russia must be assumed to be a decapitation strike, which means the automatic response is a full out launch of all strategic nuclear devices. This is not a safe & stable situation to say the least, it's why the US threw a fit when the Soviets placed missiles in Cuba and why Russia strongly objects to the eastward movement of NATO's borders.
In terms of capabilities, no, we cannot knock Russian missiles out of the air over their own land. That is fantasy shit. The Soviets were not stupid, like the US, they put most of their missile silos in the middle of the country where they can't be hit before they're launched. They're not going to let us park 50 Aegis missile ships off their northern coast either so we're not going to be doing any boost phase interceptions. We also don't know where a bunch of their missiles are since they have also have mobile launchers in addition to silos.
As for China, they're not even a threat. China is uniquely vulnerable to nuclear strikes and they know it, their population is far more concentrated around key areas than either the US or Russia, plus their agriculture and transportation networks can taken out with relative ease compared to the big 2 nuclear powers. This is why they're so touchy & aggressive when it comes to asserting their presence in their local seas, they know that it only takes a couple nuclear subs in the wrong places to cripple them for decades, if not permanently. They're not going to launch a first strike since they know they'll be annihilated in response, and there's nothing they can do about that for the foreseeable future.
Finally, Iran & North Korea. This is not the Iran of the cold war era. I don't know if you saw the Iranian missile strike on Israel, but that was one of the best demonstration strikes I've seen in my lifetime. It was carefully calculated to destroy key targets with minimum collateral damage, and everything they wanted to hit was destroyed despite everything the US and Israel did. It satisfied the calls for action in the Muslim world, proved that Iran could hit whatever it wanted to, did so with minimum collateral damage & loss of life, and it gave the diplomats on both sides an off-ramp to de-escalate the situation. IMO we don't need to worry about Iran, they know the rules of the game and they're not going to do anything stupid or reckless. North Korea is harder to read, but I don't think they're as crazy as most people believe.
