You are oversimplifying the situation.
With N.Korea, Clinton and company allowed nuclear proliferation in exchange for assurances that the technology would only be used for energy.
Of course, you and I know... never trust a commie.
So that mess was in play, plus we had to tippy-toe around the Chinese, who are the major player in North Korea's geographical area. World politics basically dictated that we handle that situation differently than we did in Iran.
Bush never made the mistake in trusting the North Koreans to keep their promise of peaceful usage of nuclear technology. Clinton holds that bag.
Here's the news coverage of it.
However, Obama seems perfectly happy to repeat Clinton's mistake in his current handling of Iran's nuclear ambitions.