“permitting them to continue to seize non-Iranian citizens”
All the people (4 I believe - not including the ex-FBI guy missing from Kish Island) detained by the regime have Iranian passports and were travelling in Iran under those passports. That’s how they were detained. Anyone carrying an Iranian passport is considered an Iranian citizen by the regime.
They knew that.
They were still not Iranian citizens and clearly, the seizure of British marines was an act of war. The Iranians like to seize hostages - so do most terrorists.