Canada wants trade with the US more than trade with Iran and thus bows to the US.
As do EU nations.
Examples:
https://www.rt.com/business/443315-swift-iran-us-sanctions/
Quote:
The Belgium-based financial messaging service added: “This step, while regrettable, has been taken in the interest of the stability and integrity of the wider global financial system.”
SWIFT’s decision further undermines EU efforts to maintain trade with Iran and save an international deal with Tehran to curtail its nuclear program, after President Donald Trump pulled the US out in May. Being cut off from SWIFT makes it difficult for Iran to get paid for exports and to pay for imports.
https://www.rt.com/business/444051-eu-fears-us-sanctions-ira...
Quote:
Earlier this week, European Justice Commissioner Vera Jourova pledged to find an effective solution, saying that technical work on creating the mechanism to allow EU trade with Iran continued.
“We Europeans cannot accept that a foreign power, not even our closest friend and ally, takes decisions over our legitimate trade with another country,” she told the European Parliament in Strasbourg, stressing that the bloc would not be cowed by probable US penalties.
Also, under Russian laws companies like Google or Facebook must keep Russian users' data in Russia; they are not complying.
They’re calling them US sanctions but the UN has also imposed sanctions on Iran. That may explain why Canada arested him. One signatory picking up a person on behalf of a more motivated one.