Pakistan would be committing a 'grave error' if it fails to punish the masterminds behind the Mumbai attacks, a noted US analyst has said, pressing Islamabad [Images] not only to take action to defuse the crisis with India but also to demonstrate that the government and not the terrorists are in charge in Islamabad.

"Pakistan must punish the masterminds behind the Mumbai [Images] attacks, not only to defuse the crisis with India, but to demonstrate that the government of Pakistan not the terrorists  will set the future course of events for the country," Lisa Curtis, Research Fellow for South Asia at the Heritage Foundation, an influential think-tank in Washington.

"It would be a grave error for Islamabad to refrain from punishing those responsible for the senseless acts of murder in Mumbai under the excuse that such action would give the appearance of Pakistan succumbing to Indian pressure," she said in a commentary.

"This is not only about the India-Pakistan relationship, nor even just about the future of the US-Pakistan relationship  it is about the future of Pakistan itself and whether its leaders can rise to the occasion to overcome the terrorist scourge that now threatens to unravel the country," she says.

Curtis notes that the political fall-out from Islamabad finally admitting Kasab [Images] was a Pakistani citizen was dramatic with Prime Minister Yousuf Raza Gilani [Images] firing his National Security Adviser Mahmud Ali Durrani for making the announcement on his own, without coordinating first with the Prime Minister's Office.

"Although we may never know the full story behind Gilani's move to fire Durrani so abruptly, the incident demonstrates just how fragile Pakistan's internal political situation remains," Curtis says.

The analyst also pointed out that Pakistan military's years of support for jihadi groups fighting in Afghanistan and India as well as intensifying linkages between Pakistani home-grown terrorists and Al-Qaeda [Images] is costing the country dearly.

"In fact, Islamabad's foreign and domestic policies have become hostage to the agenda of these irrational, deadly actors who also increasingly target Pakistani institutions," she says.

Curtis also noted that though Indian officials have declared they do not want military conflict with Pakistan, they 'also cannot tolerate lack of concrete action in Pakistan against the culprits, especially as the evidence grows ever so damning'.