I was going to say that since there are still people alive in the former Soviet Union, that it had not suffered the sort of total environmental and social collapse Diamond primarily deals with; but, indeed, the index lists "Soviet Union, collapse of, 509. And on page 509, we find, "In fact, one of the main lessons to be learned from the collapses of the Maya, Anasazi, Easter Islanders, and those other past societies (as well as from the recent collapse of the Soviet Union) is that a society's steep decline may begin only a decade or two after the society reaches its peak numbers, wealth, and power." So, there. You may consider the Soviet Union dealt with.