Yes? ICANN is part of the US, and has been strong-armed by the US government into imposing restrictive rules on gTLDs even though they appear like they're global.
Any actual evidence that the US government has control over ICANN? I know they used to have an agreement that gave the US some oversight, but as far as I know that ended a decade ago.
That may be how things work in some countries, but not in the US, even under Trump.
Let’s Encrypt evidently didn’t mean to block all of Iran, only the Iranian government, which I assume is capable of getting its own certificates: https://news.ycombinator.com/item?id=48465754
Let's Encrypt evidently meant what they said, and the evidence is the fact that they said it. And they said they were sanctioning the whole country of Iran.