I don’t think the word “coincidental” means what Donald Trump thinks it means.
Last year, Russia attacked the United States. Spies sent by Vladimir Putin, in apparent coordination with members of the Donald Trump for President campaign, worked to change the outcome of the presidential election. Iran did not attack the United States. Iran has kept its commitments
It’s not strictly true to say that the sanctions against Iran are not working. They’re working very well for the executives and wealthy investors whose fortunes are connected to the price of a barrel of oil.