The arrest in the US of Faisal Shahzad, an American of Pakistani descent, is likely to intensify pressure on Islamabad to crack down decisively on terror groups on its soil that continue to offer training for attacks in the West.

The failed attack on Times Square follows a series of alleged plots on US soil suspected to involve American citizens. Two of them were traced back to Pakistan.

In February, Najibullah Zazi, a Colorado-based airport shuttle driver, admitted to a plot to blow up New York's subway system. In December last year, five American citizens were arrested in Sargodha, Pakistan, for seeking jihadist training and plotting against American targets.

While the plots have failed, the US faces a problem that Britain also has been forced to confront with the attacks on the London transport network on 7 July 2005. Homegrown terror cells have emerged with the alleged intent of attacking targets at home and abroad, some after receiving training in Pakistan's jihadist underworld.

Pakistan is not the only source of jihadist training for Western recruits. The failed Christmas Day "underwear bomber", Umar Farouk Abdulmutallab, cast fresh light on Yemen's emergence as an al-Qa'ida base. But the continued existence of training camps in Pakistan's wild tribal areas along the Afghan border and elsewhere clearly still represents a threat.

Pakistan insists it is doing all it can to tackle the threat. Recent and mostly successful military offensives lend credence to the claims. At the same time, priorities have remained focused on the domestic threat, with militants continuing to strike across the country with vicious bombings.

At present, Pakistan lacks the necessary resources to mount effective counter-terrorism operations. The police force is poorly paid and ill-trained and there is scant coordination between different arms of the intelligence services.

Improving Pakistan's capacity to trace terror suspects will be crucial in thwarting future attacks. Western investment is helping, but will take time to yield results. But the real problem remains: unless the terrorists' much-coveted infrastructure is permanently uprooted, they will continue to attract wannabe jihadists.