Alistair Milne is a payments expert and professor at Loughborough University. Here he uses the example of the Iranian sanctions to show why banning Russian banks from Swift alone is not enough to shut Moscow out of international finance.

Since Russia’s invasion of Ukraine a curious narrative has taken hold: banning Russian banks from the Swift messaging system, a measure announced over this weekend, will somehow freeze the country out of the global financial system. The experience of financial sanctions on Iran suggests otherwise.

The US has applied, and periodically reinforced, economic sanctions on Iran for decades. From 1984 these sanctions largely targeted the Iranian oil industry. However, they were not made comprehensive until 2006, when a series of “targeted financial measures” were introduced to stop foreign banks undertaking financial transactions with Iran.