With regard to the Iranians, we know that by not talking to Iran the U. S. did not improve the situation. Today Iran is a nuclear power - it doesn't have nuclear weapons yet, but in 2001 it was not yet able to convert uranium or uranium gas, it didn't have a single centrifuge. Now it's stockpiling highly enriched uranium. So the current approach of not talking hasn't worked. There's no guarantee that if you talk you'll succeed, but if you don't talk you will fail.