Dan McCarthy observes that it is the conventional and consensus-oriented thinking of many Republican realists that has led them awry:

But the solution I sometimes hear from conservative thinkers who aren’t committed to any particular foreign policy is paradoxical. They advise working within the GOP and conservative movement: avoid upsetting anyone, and if you’re nice enough, eventually everyone will listen to you. This is exactly what has led realists—think of Powell selling the Iraq War at the UN, or Hagel’s own vote for the war—into policy failure and rhetorical inconsistency.

If there’s one glaring weakness that Republican realists have, it is their tendency to be reliable team players for their party and president. I suppose the same could be said of all partisans, but it is particularly damaging in this case, because the issues where realists have the most valuable advice to offer usually concern grave matters of war and peace. Republican realists have been at their best when they have been willing to challenge widely-held assumptions, ideological obsessions, and oversimplifications of complex problems, and they are at their worst when they end up falling in line behind those that embrace some or all of these things. Powell may be the most obvious example of the latter failure when he helped to promote a war that violated every part of the Weinberger-Powell Doctrine, but he is unfortunately far from the only one.

Even so, it is a little too easy to blame realists as a whole for much of the Republican Party’s current foreign policy woes when their influence in the past has been in steady decline for twenty years. While self-identified Republican realists have endorsed bad policies, they usually haven’t been the authors of them. The policies that they propose have much more often been sensible than they have been disastrous, and the opposite has been true of the heresy-hunters that have been trying to eliminate realism from the GOP for decades.

Realists have lost a lot of ground in the GOP, but it hasn’t been because administrations identified with them presided over any major disasters. Instead, the very things that made their preferred policies successful, especially their prudence and caution, were cast aside by a new generation of Republican leaders that no longer took these principles very seriously when they didn’t actively loathe them. Realists prize some specialized knowledge about the rest of the world, and many of their intra-party opponents encourage people to dismiss expertise as elitism and to trash knowledge of other cultures and nations as sympathy with America’s enemies. The result for Republicans is the carnival display of ignorance and demagoguery that we witnessed yesterday, and Republican realists are definitely not responsible for that.