Your all right about the nukes but that's old news
the new weapon of choice will soon be the weather, of course there are those that believe that we are already in the earliest phase of this new warfare
some extremists would go as far as to say that the earthquakes in Japan, and even Hurricane Katrina were part of this scheme however my mind requires a bit more evidence before I am comfortable with making such bold assertions.
Best example is USA HAARP
Russia is also working on building similar weapons, can't remember the project name right now
http://www.haarp.alaska.edu/http://www.youtube.com/watch?v=QkLTzesBxGEI happen to know someone who works for the USA's National Security Agency which, FYI, has authority over and immunity from every other US agency including the CIA. There are a lot of things that he cannot share with me without fearing for his life, however he has told me what he can about all this and I believe, based on our conversations as well as my own research, that its legitimate. I know these things have already been used, the only thing I do not yet understand is the full scope of their capabilities.
If there is going to be a WWIII I would bet that weather control along with advanced biological warfare would be the weapons of choice. Of course if I am right this could, most probably, kill a lot more than just 50% of the population. The scary thing is that these weapons would leave the planet in tact and readily hospitable so there is much more incentive to pursue them than there is incentive to use Nukes.
If your interested in my personal opinion, in terms of human population, I feel like some devastating event is inevitable at this point whether it be man made or naturally caused. At best we have 60 years and then were out of oil, unless we seriously jump on the green energy bandwagon right now then I have no hope that this race will have more than a populous of 500,000 million at best by, say, 2070.