The Iran sanctions are yet another sad example of the US losing the moral high ground and soft power (followed by hard power). Americans might not like hearing this but increasingly the US is seen a dangerous, untrustworthy and negative value ally. As this continues the EU block will steadily move away from the US eventually NATO will fragment and this will have serious implications for global stability.
Prior to the current return to Iran sanctions the USA had a monopoly on international payments clearance. The EU has responded by setting up an alternative system.