Nostradamus considers WW 3 to be the most imortant event in World History. This is not only due to the large loss of life during WW3, but also due to the negative changes to the environment which will last decades. It is these negative changes to the environment that will cause the death of billions of people following WW 3. 

Nostradamus also predicts a military coalition between Russia and China, that will last a few years prior to WW 3.