We got married in Sweden in 1982. I was a UK national and my wife Hungarian. We had to satisfy the authorities that the laws of our respective countries did not stop us marrying. So the reference to  "This was a result of an order from the Ministry for Foreign Affairs (Utrikesdepartementet), saying that a Hague Convention of 1902 required its signatories to enforce other countries' marriage laws on those countries' citizens." seems to have still then been in force.