There can come a point in a terrorist campaign when the insurgents discover they no longer need to rely solely upon their ability to inspire terror, but can also demonstrate their wider power by treating the authorities ranged against them with contempt. That is what the Taliban did on Monday in the Pakistani town of Dera Ismail Khan when they raided a so-called high-security jail and freed some 250 of their fellow terrorists including more than a score of their top leaders. The attack on the prison lasted several hours and appears to have been carried out with a high degree of military precision. The freeing of some of their most valued commanders is of itself a major victory for the insurgents. However, the humiliation this has imposed upon the new government of Nawaz Sharif and the security forces in Islamabad is a propaganda coup of the first order. The humbling of the Pakistan establishment is the greater because this week's assault was a virtual carbon copy of a raid on a jail nearby in Bannu in April 2012 in which more than 400 Taliban were freed. A large convoy of terrorists arrived at each prison and used powerful explosive charges, not simply to blow in the main gates but also to breach the prison wall in several places and to destroy the power supply to the facility. Thereafter, the attackers moved swiftly to bottle up a barracks for guards while targeting specific cell blocks to free their fellow terrorists. Indeed in this second attack, one of the assailants was using a loud-hailer to call out the names of the men the attackers wanted, telling them where to come to be helped to freedom. However, it is not simply that the authorities failed to learn any lessons from the first attack. Incredibly, it is now clear that at least a fortnight ago, Pakistani intelligence had picked up indications that the attack was being planned on the Dera Ismail Khan jail. The prison authorities and the local military and police commanders were all alerted. Yet as far as can be seen from the stunning success of this assault, nothing was done to prepare for it. Given that they knew the attack was coming, the security forces could have laid a major ambush for the Taliban, not only in the prison itself for when they attacked, but also along the routes that they would have used to withdraw. Done properly, the authorities could have inflicted a major blow on the insurgents, which might have persuaded them to accept the negotiations that the Sharif government is offering. As it was, this is another triumph for the men of violence, coming on top of a string of attacks which in this month alone has included an assault on the Sukkur offices of Pakistan's intelligence agency and the Karachi assassination of President Asif Ali Zadari's security chief. Nor indeed should it be assumed that Nawaz Sharif's olive branch of talks has much chance of success. The Taliban have used past negotiations and the easing of military pressure on them that these have brought as an opportunity to regroup for further violence. Only a series of very public military reversals is likely to swing the balance of power away from the terrorists. Given the pathetic shambles produced by the government security forces at Dera Ismail Khan jail on Monday, there seems little hope of that happening anytime soon.