A couple things I'd mention upon reading this thread.
Warren Buffett owns an insurance company. In his policies, he has clauses that state the policies do not cover damage from nuclear attack. Here's what he said on this topic in 2002:
May 6, 2002 Posted: 7:55 AM EDT (1155 GMT)
Investor Warren Buffett, who has major insurance holdings, says the United States faces a high risk of nuclear, chemical or biological attack.
OMAHA, Nebraska (AP) -- Investment guru Warren Buffett offered a bleak prediction for the nation's national security, saying a terrorist attack on American soil is "virtually a certainty."
Envy and dislike of the United States have fueled rage against the country even as the ability to build a nuclear device has spread, Buffett said Sunday at the final day of Berkshire Hathaway Inc.'s annual meeting.
"We're going to have something in the way of a major nuclear event in this country," said Buffett, the firm's chief operating officer. "It will happen. Whether it will happen in 10 years or 10 minutes, or 50 years ... it's virtually a certainty."
Washington and New York would be the top two targets because terrorists want to traumatize the country and kill as many people as possible, Buffett said.
Chemical or biological attacks are similarly high risks, Buffett said.
http://research.lifeboat.com/cnn.htm
This is what he said about this same topic in 2012. Here, he mentions governments as possible sources of attacks, not just terrorists:
CNBC's Becky Quick: Overall you are very optimistic about the future not only of this country but of the stock market. But if you have a list of worries, what's at the top of that list?
Warren Buffett: My biggest worry is nuclear, chemical, and biological attack of some sort, whether by a government or by a rogue. That will happen some day in our future and that will be a large tragedy to an unbelievable tragedy.
Quick: Right now it's not on the forefront of Americans' minds although a lot of things that are happening in the Middle East right now are creeping back up there.
Buffett: It'll happen sometime when it isn't on our minds just like it happened on 9-11. There are people that wish us ill and they wish us a lot of ill if they can pull it off. So nuclear, chemical, and biological knowledge is spent. There are plenty of people that wish us ill, so that is the biggest worry.
http://articles.businessinsider.com/201 ... ttack-cnbc
Moving onto the next topic, I don't recall bringing this up anywhere on the forum, but I think the nuclear war, if the war does occur that way, will start with either small suitcase nukes or devices that disperse and contaminate a limited but critical area. I believe either terrorists or robots will be involved in executing these attacks, but governments will be behind the attacks. They will be difficult to trace, but I think nuclear material is ultimately traceable as to its source. You guys please correct me if I'm wrong on this. I found this article that describes the current state of the art (perhaps traceable, perhaps not it appears).
http://www.guardian.co.uk/uk/2012/mar/2 ... -ministers
If nuclear material can be used that is not ultimately traceable, then I think limited scale nuclear war as an initial strategy is pretty much a done deal. But anyway, my point is that if the Chinese want to retaliate against the US for whatever reason, as an example, they will use a terrorist organization. They may smuggle a suitcase nuke in through, say, the border of Mexico, then detonate it somewhere nearby that has critical infrastructure, like Houston. Or the terrorists may take it all the way to Washington or New York if they can, but I'm not sure if they would be able to get it that far without it being detected. As another example, the Russians can be behind smuggling and detonating a suitcase nuke and make it look like the Chinese did it. The possibilities are endless.
Anyway, once something like this is accomplished in one or several critical cities, it would put the targeted country in a bind as to how to respond. I believe the ultimate response would be to launch a larger scale attack against whoever is supected to be the source.
I would also mention that if bioweapons with pandemic effects can be perfected soon enough, then I strongly believe those will become the weapons of choice and they will be delivered in much the same manner, with infected terrorists spreading the pandemic via public transportation systems and so on.