The capture of city after city by the Sunni jihadists in Iraq has been due, it has been held in some quarters, to the collapse of the Government's forces rather than the strategy of an insurgent group known more for its proclivity for violence than planning.
However, the actions of the Islamic State of Iraq and the Levant (Isis) have been anything but ad hoc in either Iraq or Syria through which its fighters have cut a bloody swathe; its success against the forces of Bashar al-Assad and the Government of Nouri al-Maliki has, indeed, followed detailed work on tactics.
The current offensive - which has led to Isis capturing territory from Mosul to the outskirts of Samarra and towns in Diyala while, at the same time, consolidating past gains in Anbar including Fallujah - bears remarkable similarities to operational plans drawn up by the group's predecessor, the Islamic State in Iraq (ISI) eight years ago.
The first evidence of the "Baghdad Belts" mission was discovered in a roughly drawn map found on the body of Abu Musab al-Zarqawi, the man who turned ISI into a ferocious enemy of the West, after he was killed in a US air strike in June 2006. Further evidence emerged of how the aim was to seize key areas around the capital and funnel through gunmen, weapons, car bombs and surface-to-air missiles into the city.
The death of Zarqawi and then the "surge" of US forces under General David Petraeus stopped the implementation of that plan. However, one of the men who played a part in drawing it up at the time, Abu Suleiman al-Nasser, became the "war minister" in Isis.