Carter decides to more firmly stand with the shah.
Exactly how many badly made helicopters is he going to send this time?
You don't stop a major popular revolution by "standing firmly", you need an army. Which we weren't ready to send. The only result of Carter taking a stand on the Shah with no military force to back it up is to make the Iranians dislike us more, if possible.
Anyhoo, the US was an ally of convenience to the Shah: being an ally didn't prevent him from jumping in right away on the oil embargo. And he was, after all, dying of cancer. There's no guarantee that his heir would be able to hold onto the throne in the long run, even if his dad was able to temporarily squash rebellion - the Shah's regime was _quite_ unpopular, and killing Khomeini would not change that- indeed, he would ironically have a much better reputation than OTL, as a martyr to the evil of the Shah. (Heck, the Shah's heir might take up an anti-US, anti-Israel populist line to help keep himself on the throne).
(Heh. There were some strong leftist elements in the Revolution - without Khomeini to rally the theocrats, perhaps the failure of the 1979 revolution just means the 1985 one, the one where Iran ends up a left-wing dictatorship, succeeds. What will this do to Gorbachev's efforts to patch things up with the US?)
If you want the Iranian-in-the-street as being pro-US, make Mossadeq a more plausible anti-Communist and have the US support him vs. the UK when he tries to nationalize the oil industry. The Iranians had no beef with the US before then, and will be gratreful for the support.
Of course, US support for Israel will still annoy the more Islamicist Iranians, but as they're neither Sunnis or Arabs (there's a certain still-existing animosity between Iranians and Arabs: when the Iran-Iraq war got started, Saddam invoked the battle in which the early Arab armies crushed the Zoroastran Persian army, and the Iranians haven't forgot the incident that eliminated them as an independent political entity for centuries), it will annoy Iranians less (Turkey, OTL, doesn't get along too badly with Israel despite being a Muslim country).
So, Iran 1980-something: a fairly corrupt country (oil wealth always seems to do that), but with a better distribution of wealth, a semi-democratic government (think Mexico at the time) and an annoyingly powerful Islamic movement, but with a less autocratic government which makes the right Islamic noises and has historical legitimacy, they have fewer prospects for taking over the government, no matter how annoyed some people are by such horrors as land reform and education for women. They don't like Israel, but they have diplomatic relations with it, and even engage in some commercial relations with it (the
Protocols still does a fair business in Tehran bookstores, however). They are historically friendly with the US, (although there was a bit of a bad patch over Vietnam - the Iranians don't like anything that looks like colonialism) and become a lot more so after the USSR invades Afganistan.
(Hm. Saddam OTL sometimes tilted pro-USSR to counterbalance US support for the Iranian regime. This will continue in this TL, and the Scary Maps we will be shown on TV won't show the USSR continuing south through Pakistan, but rather catching Iran in a pincers movement...)
Bruce