I understand the sentiments. I also did see where the article talks about his heritage and ancencestry in Iran.
I have heartfelt sympathy for this guy and his family. But this is not a couple of thrill seeking hikers in the mountains. This is a US Marine in the midst of the worst of times to be an American in Iran, let alone an American soldier.
All covert CIA operatives have copious cover stories. It comes with the territory. I have to be reasonable, objective and logical. Either this was very poor judgment for this marine to go visiting his grandparents or he was caught and that was his cover story.
If I were recruiting agents for the CIA, I would only dream of finding someone with the capable skills that was from Iran, knew the country and customs and spoke the language perfectly.
Again, you have to ask, why would an active marine take leave time to sneak into Iran to see his Grandparents. He certainly didn't go in uniform.
I do keep open the possibility that the guy did just use horrible judgment and was naive to the fact that an American marine in Iran was a high risk recipe for disaster.
Considering all the mysterious nuclear research site explosions in Iran in the past several months, I hope we are somehow helping covertly to disrupt their weaponization of nuclear material. I can't discount the possibility that this marine was somehow part of the covert team that I hope is active in Iran for us. If so, he will be one of the un-named heroes that never gets recognized for the sacrifices he makes for us.
I do pray for his safe return home and hope the president does something to facilitate that.
I've had friends who've wanted to visit China but were unable because they were former US military (their visa requests were denied). Granted this was over 15 years ago, but based on entry requirements of many countries considered "less-than-friendly" to the United States, I agree with your reasoning and tend to lean more towards your second hypothesis.