Based on how Russia has bullied and invaded Ukraine after they gave up their Soviet-era nukes, what are the odds that Kim will fully denuclearize? Scuttle the first generation testing and development environment, a low cost, but who really thinks he'll get rid of the existing weapons or halt further development? But like with Iran-Contra under Reagan, what is the underlying priority of Republican concerns? To make Trump look better in the short term, not worry about the long term?
Different situation, same basic issue: Reagan rode into power in large part criticizing how Carter handled the Iranian hostage situation. But how many Republicans today care that Reagan also broke the law & sold weapons to Iran, to fund arming the Contras in Central America? My guess is fewer than 1% of Republicans remember or care about how they strengthened Iran under Reagan... but Obama supporting the Iranian framework is just awful - just ask Netanyahu.