Probably the biggest foreign policy blunder of the second Bush administration after the invasion of Iraq was something few think about that happened within the first two months of Bush becoming president. Against the advice of Sec. of State Colin Powell but at the urging of Cheney and Rumsfeld, when South Korean President Kim Dae-Jung arrived for a formal state dinner in March, 2001, he was given the cold shoulder on nuclear negotiations with North Korea, which had been going on since 1994. The DPRK was a signatory to the NNPT and had shut down its nuclear weapons program. Further negotiations were ongoing, and Kim wanted support for continuing them, support Powell had assured him the US would provide. This was not forthcoming in March, 2001, leading to outbursts of anger in the ROK against the US.
The stated theory of Cheney and Rumsfeld was that the DPRK was on the verge of collapse like the USSR had been a few years earlier. All that was needed to bring about regime change was to apply more pressure through sanctions and to abandon the nuclear weapons negotiations. Easy as pie.
What then followed over several years was that the North Korea withdrew from the NNPT, expelled foreign observers, restarted all its nuclear reactors, and within a few years began producing nuclear bombs, which it has tested on several occasions since. The nuclear aresenal of the DPRK may not amount to much, but they are now a bona fide nuclear weapons power, and their regime has not fallen, despite the pollyanna predictions of Cheney and Rumsfeld. I can think of few foreign policy failures by the US bigger than this one in the last quarter century, although few talk about it. But, it was a total flop, making a bad situation far more dangerous.
OK, so this approach of Cheney and Rumsfeld to North Korea looks to me prettty much like the current attitudes of most of the GOP critics of Obama's negotiations with Iran, not to mention the views of Israeli PM BiBi Nethanyahu. Oh, if only we apply tighter sanctions, we shall get a better deal than the one Obama has gotten (or nearly gotten, as important details apparently remain to be pinned down, but the opponents of the deal want to "blow it ups" (to quote Scott Walker) before ever that can happen).
Offhand, it looks to me that the outcome of following these critics will end up resembling what happened with North Korea. Iran will not collapse. If we "blow up the deal," our P+1 negotiation partners will end their sanctions, and the remaining US unilateral sanctions, which have been in place since 1979, will not do doodley-squat. If Israel and the US insist on aggressing more actively against Iran militarily or however, Supreme Leader Khamenei may well withdraw his anti-nuclear wepaons fatwas, Iran might withdraw from the NNPT and expel all current observers, and, well, follow the path of North Korea and begin building nuclear weapons for which indeed they do have the capcity to do. Is there a stupider path out there to follow? Oh yeah, we could start bombing them or invade them, thus replicating the one foreign policy blunder of George W. Bush that exceeded his ending of the nuclear weapons negotiations with North Korea.