As one of the participants in the programme, I did not hear him give an estimate of when we would be able to leave. He used the standard government formulation of "we shall stay until the job is done", but failed to define the job. He did say that he thought it would take 5 to 10 years to establish democracy. If that is the job, then you could make a deduction about the task length. In any event, that is probably an optimistic assessment based on Balkans experience.
I saw the Aaronovitch character at a small current affairs discussion two years ago. He laughed off my question about the difference between battlefield and strategic chemical weapons and called my missus "naiive" when she challenged him on spin and lies.
If he makes a U turn it will be akin to a supertanker turning round