The US and Israel have a long standing partnership. During the cold war the USSR backed Syria and Egypt (E.g.) and the US backed Israel. That was not different than other places in the world where the US pushed back against soviet expansion. Unlike Europe though there was never a formal defense pact. Also unlike Europe there were actual wars with people getting killed.

I'm not sure the US "created" the religious extremist government in Iran. It's a complicated story. But the Shah was hated and like other similar dictators to date the US was happy to support that regime and turn a blind eye to the atrocities against the Iranian citizenry. Just like it is happy to work with other dictatorial regimes today as long as their interests align. When the revolution happened the Ayatollah was already well positioned to take advantage of the situation. Many of the people who rose up were eventually lined up against the wall and executed, like tends to happen in these revolutions.