I am curious as to what "on the ropes" means. I have asked before, has a government ever fallen due to sanctions? Can you name the times?
North Korea is under tremendous sanctions. At one time it was the industrial heart of Korea, the South was the agrarian Korea. Below is a picture from space at night. North Korea can't even light up its cities. Yet I see no evidence they are conceding a single thing to the rest of the world. Iran has religious fervor, they will gladly forgo the latest TVs if that is what it takes to export their crazed ideology. My guess, I haven't seen stats, the vast majority of people killed in the October attack were killed by AK47s and grenades. Neither requires very much cost at all. My guess is you yourself could have funded that part of the attack. Probably even the motorized gliders as well. I'm not arguing against sanctions, but they have to be part of an overall plan that quite probably includes negotiation or military action.
We have had sanctions on North Korea, Venezuela, Iraq, Cuba, Syria, and now Russia. Serbia's economy went from $24 billion in 1990 to $8.6 billion in 2000 because of NATO sanctions, yet it was war that changed the situation on the ground. I wish sanctions worked, I had been a huge proponent. But once we try them a dozen times to no success it becomes obvious they are a weak tool. Countries that want to be part of the global community might be responsive. Pariahs don't care, and seem to have an opposite effect. They bolster the leadership by making them seem tough by standing up to the evil US/NATO/UN. Nothing allows a dictator a better internal excuse for failure than blaming outside forces.
We might as well sanction enemies, at least then we are sending them America dollars to do what we don't like. But we can't fool ourselves, withholding American dollars isn't going to change governments nor is it going to change actions. I look forward to your list of nations that have significantly altered they behavior to sanctions to prove that wrong.