--Neoconservatism is an aberration--
We'll never know. Most "neocons" left (or had already left) the Administration after the 2004 elections. They were probably dissatisfied that their plan had NOT been fully implemented, due to opposition by Powell and the rest of the State Dept.
The only direction to go after the fall of Baghdad was forward (i.e. into Damascus). After Assad saw that "insurgents" were able to enter Iraq from Syria with impunity, and Iran felt emboldened to prop up Sadr et al., the Coalition's momentum was stopped in its tracks.
Now, the only solution to Iraq may be regime change (not necessarily by military means)in Tehran and Damascus. The only Americans in government with the guts to support such policies would be appropriately called "NEO-NEOCONS". They may yet emerge; the next decade will be "interesting" to say the least.
And socialism didn't fail so much as it was never really tried.