Iran since the Islamic revolution has employed the tactic of arresting Westerners in a bid to extract concessions from its foes, in a strategy of "hostage diplomacy" that has long presented Europe and the United States with a dilemma, observers say.

Iranian authorities this week released two French nationals, Cecile Kohler and Jacques Paris, from jail in Tehran after more than three years.

They had been convicted on charges of espionage but their families said they were innocent tourists unwittingly caught up in a wider game being played out between Tehran and the West.

France described the pair, as well as several other French nationals detained in Iran who were recently released, as "state hostages". Over the last years, dozens of Europeans and Americans have been detained in similar circumstances.

The strategy has long antecedents, going back to the seizure of the US embassy in Tehran in November 1979 by Islamist radicals in the wake of the revolution, which saw dozens of Americans held for 444 days into early 1981.

"Iran has pursued hostage diplomacy since the founding of the Islamic Republic in 1979," said........

© Al Monitor