iran - and many other countries in the world - could take you happily as a hostage if your government is considered an enemy.
N.B. the argument that Iran will falsely label you a 'spy' feels weak to me given the order of magnitude of such detentions in recent history is in the tens. It would be equally improbably that most of these detentions were false positives as plenty of foreign intelligence operations happen in any country. Especially given the amount of foreign-intelligence related sabotage in recent Iranian history.
Extremely respected engineer both in Iran and America, ran tech initiatives for youths in Iran, a key figure in international text rendering. No political activity, but he got arrested and coerced anyway because the Iranian government wanted to force him to become a spy.
He managed to escape, but it ruined his life and career.