The success suggests improved intelligence cooperation between Pakistan and the US. The US has superb technical collection capabilities, but has lacked timely and accurate human intelligence. Significantly, the attack was not condemned by Pakistan which has protested in the past about US drone strikes in the FATA.

Mehsud's death is a major success for counterterrorism, but there are competent potential successors competing to replace him. A meeting of the leadership council of the TTP is currently under way to appoint a successor. The succession process has been wracked with violence, with one or more of the leading contenders being killed. [Wali-ur-Rehman, a cousin and deputy to Baitullah Mehsud from the Alizai Mehsud tribe, is reported to have killed Hakeemullah Mehsud, commander of three of seven of the tribal agencies in the FATA. Hakeemullah was Mehsuds most likely successor. Wali may also have been killed. Other leadership contenders are Hakim Ullah, a commander known for recruiting and training suicide bombers, and Azmat Ullah. Both were close associates of Mehsud.] Mehsud had a flair for publicity, sometimes being seen in a captured Humvee, although he was also very security conscious. A challenge for the new leader will be how to impose his personality on the Pashtun tribes in Waziristan without attracting CIA air strikes onto the homes of his relatives.

Whoever takes over the TTP, the Pashtun in mountainous Waziristan will remain fiercely independent. They will continue to oppose Pakistans pro-Western government and support resurgent Taliban activities across the border against the infidel forces in Afghanistan. Whether Mehsud's successor will be as supportive of al-Qaeda remains to be seen.

Turning now to Indonesia, Noordin Mohammed Top is or possibly was the Malaysian leader of al-Qaeda for Indonesia, a splinter group that broke away from Jemaah Islamiyah and became independent of JI. Although the most recent name of the group suggests a link to al-Qaeda central, there may in fact be no direct link. Top, like all jihadists, is aware of the value of being associated with a respected global brand. The groups aim remains the use of violence to create a fundamentalist emirate in Southeast Asia, based on an Indonesian Muslim heartland.

Top is Southeast Asia's most wanted man because of his role in the 2003, 2004, 2005 and 2009 suicide bombings that killed seven Australians. Contrary to much of the Australian media reporting, he was not involved in the more deadly 2002 Bali bombing that killed 88 Australians.

Noordin was initially reported killed after a 16-hour siege last week at a house in Temanggung, Central Java. Police and some security analysts are now ruling out Top as the man killed in the house. [The Jakarta Globe for example quoted a senior official from the counterterrorism unit Detachment 88 as saying the dead man is not Top based on fingerprints, facial features and body posture. Damage to the body has precluded accurate facial recognition. On the other hand, other police are quoted by the Jakarta Post as saying that the raid on the house took place following a week of surveillance during which police positively identified Top.] The body is being held at the police hospital in Kramat Jati, East Jakarta pending DNA confirmation of its identity.

Organisationally, Tops group has no clear structure beyond an inner circle that consists of Top and a small number of close associates. The rest of the group consists of ad hoc cells that may come together for specific operations. In all, it may total no more than 30 individuals. Members of other Islamist groups cooperate with Top's group and seek its expertise.

For example, the 2004 Australian embassy attack in Jakarta was planned by Top, but carried out by members of Ring Banten, a Darul Islam cell from West Java. The 2007 aborted attack on a backpacker cafe{aac} at Bukit Tingi was probably facilitated by Top's deputy Reno, but was to have been carried out by an anti-Christian group.

[Police Chief General Danuri claimed that two men shot dead last Friday night in Bekasi, on the southeastern outskirts of Jakarta, were linked to Top and involved in a plot to vehicle bomb the nearby home of President Susilo Bambang Yudhoyono.

Top had ceased to favour vehicle bombs and the claim suggests spin doctoring by the President's media staff.] If or when Top is killed, the most likely successor would be Reno, alias Tedi, from Wonogiri, Central Java. Reno studied bomb-making with Malaysian master bomb-maker Azahari (killed in November 2005) and has been active in Top's cell ever since.

Assuming that Top is not dead, it seems likely that he will attempt to leave Central Java and head for sanctuary in the southern Philippines. JI members have felt obliged to shelter Top as long as he did not re-engage in violence JI now being committed to non-violent political change but the Marriott and Ritz-Carlton bombings will probably have made his situation in Java less tenable.

The death of Mehsud and Top would be seen as a major plus for counterterrorism efforts, but both can be replaced by other experienced individuals. The death of either will be followed by a hiatus in suicide bombings, but the enduring Islamist aims of their organisations will continue to drive the terrorist violence in Pakistan and Indonesia.

Clive Williams is a Visiting Fellow at the Australian National University's Strategic and Defence Studies Centre.