[tome]

It's not a prerequisite. It's just that a substantial proportion of the people of Iran are secular (unlike Saudia Arabia).

[bogomipz]

That's exactly my question why does it matter if their government is secular or not in order for the US to have it as a friend or ally?

[tome]

Unless you have a good reason otherwise, I'm inclined to believe that a secular government will be a more valuable ally than an Islamist one!