The chronological order of these events is as follows:
1. The Russian Revolution (iv) in 1917, which led to the creation of the Soviet Union.
2. The disintegration of the Soviet Union (iii) occurred in 1991.
3. The fall of the Berlin Wall (ii) happened in 1989.
4. The Soviet invasion of Afghanistan (i) took place in 1979.
Thus, the correct order is "iv, iii, ii, i."