Something like Northern Vietnam won their war. After suffering significant damage, and facing the possibility of even larger, unacceptable damage, America roll back, leaving Middle East and accepting Iranian peace terms.How do you see Iran "winning" this war? In what possible way does that take place?
One of the simpliest ways to do it - on the current NPT-conference, both Iran and Russia declare they are quitting NPT, and Russia sell Iran brand new nukes with delivery systems.
If America want to continue fight this war - at least dozen of American cities will be obliterated.