In this case, the US did play its role, because Iran wanted to nationalize its resources so BP could not lift the resources without paying a full price.
Getting Iran back in the hands of Iranians is rectifying a wrong.
The shah negotiated a better deal than the previous dynasty had signed with the British. He’d plan to nationalize the oil industry in 1979 when that agreement was up for renewal, but the mullahs swept away the government and the rest is history.