The Israelis are involved, too, and they aren't saying that, either.
They don't want to admit it. That's considered poor form. For instance, to accuse Israel of funding the opposition acknowledges the influence of Israel within the country.
And yet when these are over, when the memoirs are written, the operatives always brag about their involvement.
For crissake, the US has told us it is meddling with Iran, is trying to destabilize it. Announced that for the world. This is denial on the level of "Bush didn't lie".