This is from the Huffpost but it's an interview with actual names. Discount it if you want, but it hits the points Bedell and Hawk have been making.
How difficult would it have been to actually get tougher sanctions against Iran into place?
Elizabeth Rosenberg: Tougher sanctions require international collaboration. Right now, while there may have been an appetite among a number of policymakers in the United States for tougher sanctions, the appetite is not there among a number of really important international financial jurisdictions. And if they don’t go along, they become weak links or avenues for circumvention for Iran.
Joe DeThomas: I guess you could say, ‘Well, we could have put a full trade embargo on Iran and no oil sales. No sales of any goods of any kind. Some kind of massive economic embargo.’ I don’t know of anybody outside of Israel who would have supported that. I don’t know of any other country who would have gone willingly there.
So when you say tougher sanctions, the only way they could have been done would have been, in effect, unilateral U.S. sanctions that we leveraged the rest of the world into supporting.
Was that possible?
JD: I don’t think it would have been possible to go much farther than the sanctions that exist now without a major confrontation with another major economic player.
Why not maintain the multilateral sanctions regime and make our unilateral sanctions against Iran more aggressive?
ER: That, to me, sounds... symbolic and not necessarily economically effective. Unilateral sanctions on Iran restrict U.S. people and companies from doing business with Iranian entities. But they already can’t do business with those entities, because of the embargo we have had for decades. It is the secondary-effect sanctions that have had a huge economic impact. But imposing more secondary sanctions would come down hard on our allies, including other P5+1 negotiating partners. It wouldn’t have gone over well with them.
JD: If you want to see an example of what could happen, go back to the '90s, when we and the Europeans disagreed about U.S. unilateral sanctions on Iran, and we came very close to a U.S.-European trade war over them. And we ended up having to blink.