IIUC, Webb wrote his response. Seems to me that raising the Korea example to justify withdrawal was a huge mistake that the GOP should pounce all over. Now that N. Korea has become the first rogue state to acquire nuke weapons, one of the biggest proliferation threats, and a loose cannon capable of nuke blackmail against Japan (and shortly our west coast) that Korea solution doesn't appear to have worked out so well. Do we want to replicate that in Iraq, where if we leave half the country effectively becomes Iran right as they are about to acquire nukes?
I really don't think North Korea becoming a rogue nuke state 55 years later, opposed by its sponser state, China, was predictible. Rogue states come and go.