Bombing season in Bali?

It acknowledges the era of large organisations is over and urges Muslims everywhere to form cells, with just a handful of members in each. It mandates a strict division of labour - a person with weapons expertise, another experienced in intelligence gathering and security, and at least one other with computer skills. The leader should be significantly older than the others, be physically strong, have religious authority, military training and experience.

There are strict guidelines for recruiting new members, including a number of tests and activities they must undertake. Members should be physically fit and the manual suggests this can be achieved by joining sports clubs. A tactic used by some groups in Indonesia has been to form nature lovers’ societies, which can safely head into remote areas for training without arousing suspicion.

This and other calls-to-arms which circulate freely within Indonesia stress the argument that terrorism is the only effective tactic that can be used against the might of the “Crusader-Zionist alliance”. The literature promotes the theory that winning a clash of civilisations for the West is official United States policy.

“All Muslims and Muslim movements are going to be targeted and Islam has to be united in order to fight back,” one passage says.

Another worrying development in the wake of the arrest of JI leaders concerns the composition of the remnant groups. ICG has discovered that not only has the average age of the membership dropped considerably, but so has its background. In the past JI’s leadership contained a significant proportion of “Afghan alumni” - recruits who had received training in weaponry and tactics in Afghanistan. Over the past three years they have increasingly given way to veterans of the sectarian conflicts in Ambon and Poso.

Having been involved in sometimes brutal fighting, these newcomers may be even more willing to use violence against civilians than their predecessors. Ominously, the extremists are now targeting the Indonesian Government and its supporters, which they see as toadies of the US and its allies.

What then is the strength of the JI remnants in Indonesia, and have their aims been modified to meet their changed circumstances? The International Crisis Group estimates that at its height JI had no more than 2,000 committed members and about the same number of supporters.

The ultimate aim of the mainstream is still the establishment of Dar-es-Islam, a single Moslem state stretching from North Africa, through the Middle East and South Asia and taking in Indonesia. However Ms Jones suggests the motivation for the independent cells and for individuals such as Noordin Mohammed Top is less ambitious but infinitely more practical.

“They want to make Western nations tremble,” she said. This involves the disruption of the way of life we take for granted, such as our access to travel, our commitment to free speech and generally liberal values in an open society.

As has been proved by the chaos at Heathrow and other airports following the foiling of a plot to smuggle bomb-making materials on to airliners in hand luggage, this is a goal that can be achieved even by a botched operation in an increasingly nervous and beleaguered world.