I think we have abundant anecdotal evidence of how ordinary Iranians are putting less and less faith in the party line, if you'll allow me the expression.
One of the most popular TV programs that is being followed inside Iran is broadcast by a TV station that is based in a European country: Manoto TV. It is a satirical program that makes tremendous fun of the regime and its leaders. We know from the experience of the Cold War that at some point, even under the worst repressive regimes, the people will stop believing what they're told. They will know they're being lied to.
The fact that satire and jokes are so pervasive inside Iran today about the regime and its leaders tells us something about the extent to which Iranians are prepared to believe what they're told. Again, it's anecdotal evidence.
On the specific question of sanctions and the regime trying to deflect the concerns of its population by blaming the west or Israel, or both, it's interesting that the regime so far has been denying that sanctions have had any impact inside the country.
If you are an ordinary Iranian and you can't afford to buy meat more than once a month, and you have to take up an extra job or two in order to pay your bills, and even as a government employee you see your revenues profoundly eroded by inflation and the devaluation of the currency, and you're told by your government that all of your suffering is not caused by the outside pressure imposed by sanctions, you must obviously conclude that it's the incompetence and mismanagement of the government that is causing your suffering.
I think that if you take all of this combined, it's quite clear that very few people inside Iran are prepared to believe what they're told. The question is how you leverage this widespread lack of confidence in their government to make things change inside the country.