Re: "...They could have stopped all exports/imports with Iran and hurt their economy..."
Just the opposite is the case.
The U.S.A., the UK, the EU, and the new Russia, are all up to their eyeballs in Iran, usually involved in very lucrative contracts doing such things as constructing nuclear reactors, supplying parts to build the gyroscopes necessary to enrich uranium, building underground bunkers & tunnels, etc...
Our very own Halliburton Corporation has been actively engaged doing exactly those things (including assisting North Korea in their bomb acquisitions) for quite a number of years now. All completely legal. Can not be prosecuted.
Why?
Corporate Law & Tax Codes allow Halliburton & others to set up dummy "fronts" in Bermuda, Cayman Islands, etc., and then work day & night to make their fortunes by building infrastructure for terrorist and dictatorial regimes which call for the destruction of the U.S. & Israel.
Follow the money. Check the facts.
It was Germany who constructed all of Saddam Hussein's impenetrable underground bunker facilities, by the way.
Clinton arranged for Halliburton to enrich themselves by constructing the nuclear generators and laboratories for North Korea.
And, guess who constructed the intricate labyrnths of underground bases, bunkers, & tunnels, in Afghanistan for use by the Taliban?
Don't believe it?
As the once famous comic strip "Pogo" once so aptly stated:
"I've seen the enemy! And it is us!"