Just so you know, foreigners in the USA legally have either a SS# or a tax ID number. So, my best guess is that you are either dealing with an undocumented alien or some sort of criminal or really undesirable tenant who is pretending he is from outside the country with no identification so that you can not screen him
Or it is one of those Nigerian scams.
People who offer a full year in advance are people like drug dealers, alien smugglers looking to rent a drop house, porn producers, felons, terrorists, and people with outrageously bad credit in combination with horrible landlord references. They are people who don't want you checking on them and they are people who don't want you coming around ant looking at your house for a full year.
Normal honest people would never even think to offer a year in advance.