It's simple--they murder an opposition figure and blame it on their own democratic opposition. They use it as an excuse to wage terror on their opponents, while blaming Israel, and ridding themselves of an opposition figure to boot. And this is a regime about to get nuclear weapons??? Better watch out world, we've seen this movie before.
Turkish warplanes destroy PKK targets in northern Iraq, say military sources (Reuters)
from the article: Iran: Israel, U.S. killed pro-Mousavi nuclear scientist