npub1ne57l8vepvgjyjpjtzrknaugghjqm6cupy936gkgflp20mn54caqtfyruy (npub1ne5…yruy) I blame Bush Jr.
He chose to focus on north Korea. Arguably because it was the easier and simpler problem.
Iran has been quite clever in literally burying their nuclear program, and in claiming it's just for power. They spotted the loophole in the antiproliferation treaties.
This has been building for quite a while.