Depends. I'd say God would prefer Iran over the USA. The only thing that gives the USA preference over Iran is the fact that it supports Israel/Jews to its merit. Iran is a conservative, religious, modest society and is very similar to Judaism minus the jihadi killings and terrorism. The USA also spreads and funds terrorism so the USA is a big fat lying hypocrite. Iran is probably more honest than the US is! At least its honest abouts its intentions. To Iran's D-merit is fights against the Jewish state of Israel and threatens to annihilate its citizens.
Trying to kill the Jews is the worst sin a non-Jew can do to be honest. Adultery, homosexuality, pedophilia is not as bad as attempting to kill Jews. Jews can be zionists, communists, capitalists etc. At the end of the day they are still Jews and the fundamental route of hatred Iran has for Israel is that it is a "Jewish" country. Labels like Zionists are just a smokescreen. The law of Islam is: A Muslim can usurp your rights and overthrow another country or religion but God forbid! you should do it to them. You are not allowed to replace an Islamic country or land with anything that is considered 'kufr' disbelief. Islam is about eradicating disbelief and our spreading beliefs which are not Islam is considered heresy.
Just as Jews claim Israel is an ancient homeland, Muslims claim that once a place is Islamic territory it can never go back to the hands of non-Muslims or infidels. This isn't me spreading hate this is simply what the Quran and Hadith teach. I am more than willing to give examples to Muslims if they need examples.