From Prof Dennis J.D. Sandole.

Sir, General David Petraeus’ “surge” in Iraq, measured in terms of number of attacks and of US and Iraqi fatalities, has been a success, more so than many of its supporters had thought possible. But it is also true that the window of opportunity provided by this success in increasing “negative peace” (eg, reductions in hostilities) has not been maximised by Iraqi leaders’ promised efforts to achieve reconciliation among the Sunni, Shia and Kurdish factions (“Iraq surge brings a lull in violence but no reconciliation”, January 7).