This is a welcome change, and has great significance not just for India-Pakistan relations, but for the future of Pakistan itself. This is probably the first time that any government, apart from Libya, has admitted that its nationals were involved in a terrorist act.

The Pakistan government has indeed come a long, long way from first denying altogether that captured terrorist Amir Ajmal Kasab [Images] is a Pakistani national, and then practising other forms of evasion and prevarication, all calculated to duck its responsibility for acting against terrorists.

As recently as February 9, its cabinet's Defence Coordination Committee -- which includes the services chiefs and the head of the Inter-Services Intelligence agency -- said the government would register a case against the attackers, but demanded 'substantial evidence' from India, without which, 'it will be exceedingly difficult to complete the investigation...'

During the past fortnight, there were leaks to the Pakistani media suggesting that Pakistan's Federal Investigation Agency was going to announce that there was no evidence that any of the attackers were Lashkar-e-Tayiba [Images] members, but instead, that the conspiracy was planned outside Pakistan -- as if that absolved Islamabad of responsibility or negated the central reality, namely, that the main attackers were Pakistanis.

What explains this dramatic shift? There have been speculative stories suggesting that Pakistan 'blinked' because the United States threatened to cut off aid to Islamabad unless it comes clean. This is a frivolous argument, which fails to comprehend either the complex nature of the US-India-Pakistan relationship or the reality that States don't premise their aid programmes on other, especially third, governments' needs and desires.

The plain truth is that the US needs Islamabad's cooperation in the war against the Taliban-Al Qaeda in Afghanistan and in Pakistan's border areas. At the same time, Washington has considerable leverage on Pakistan. But it's clear that last Wednesday night's telephone call from US President Barack Obama [Images] to President Asif Ali Zardari [Images] played a role. As did Obama's special representative Richard Holbrooke's talks with Pakistani leaders during his visit to the region. Holbrooke is known as a hard-driving diplomat, or as former Deputy Secretary of State Strobe Talbott put it, 'the equivalent of a hydrogen bomb' in diplomacy!

No less important is the incredible nature of Pakistan's earlier contentions about the origins of the attack, and the solid, incontrovertible evidence contained in India's Mumbai dossier and the diplomatic offensive it mounted.

Pakistan's contentions did stretch credulity. Even if the plot was hatched outside Pakistan, some if not all of its executors were Pakistanis. Naming Austria or Spain as the conspiracy site only suggests the existence of a supra-national jihadi network, it doesn't exonerate Pakistan. Many past terrorist attacks too had a Pakistan link. British Prime Minister Gordon Brown has said that 75 percent of the most serious terror plots being investigated by UK authorities have links to Pakistan.

Islamabad has wisely recognised the flaws in its earlier case. But it still continues to deny that the terrorists were trained by and were acting at the behest of a well-organised group. Rather, it still emphasises the central role of individuals. But it's simply inconceivable that a handful of individuals could have conducted the attacks without being guided by a highly inspired network with a broad political agenda, including promoting pro-Taliban interests and provoking rivalry between India and Pakistan, as well widening the communal divide within India.

All material facts suggest that the attackers were rigorously trained in armed combat, maritime navigation, and use of sophisticated communications techniques including satellite phones and Global Positioning Systems.

The evidence provided in the Indian dossier was nothing if not substantial. One only has to browse through the dossier (external link) to convince oneself of its exceptionally high quality. Apart from information gathered from Kasab's confessions, this includes the names and specific addresses of some of the attackers, and above all, a rich body of circumstantial evidence which will stand legal scrutiny in any civilised country.

The latter includes GPS records recovered from fishing trawler M V Kuber; photographs of armaments and personal effects such as garments, powdered milk cartons and toiletries, with Pakistani markings; and money trails linking Pakistan-based operators to the purchase of a Voice over Internet Protocol platform routed through Europe.

To its credit, Pakistan has confirmed some of this evidence, named a new terrorist figure, Hammad Amin Sadiq, as a key player, and arrested six suspects, including Zaki-ur-Rehman Lakhwi. It has also identified three boats in which the attackers travelled from Karachi.

Adviser to the interior ministry Rahman Malik says Pakistan has raised 30 issues seeking more data and information from India, including DNA samples and fingerprints on the rubber dinghies on which the attackers landed in Mumbai, their diaries and other evidence, Kasab's interrogation reports, and transcripts of intercepted conversations between the attackers and their handlers, some of whom are identified by India as belonging to the Lashkar. These demands, or 'requests' as Malik put it, appear reasonable.

India has welcomed the change in the Pakistani position and promised to share whatever information it can. Pakistan has finally shown it is acting in good faith, although it must go farther -- by establishing the attackers' links with jihadi networks and identifying and prosecuting those who trained and guided them. This should lay the basis for a cooperative approach and the joint investigation that Islamabad has been calling for.

This must be conducted with the utmost sincerity. Anything less will damage Pakistan's global stature and credibility. Tackling Pakistan -- a nuclear weapons State hurtling towards chaos, and yet key to the objective of pacifying Afghanistan -- is Obama's greatest foreign policy challenge. According to his aides, Pakistan is the nation that really 'scares' him. This international image is deeply unflattering.

That apart, a strategy based on deception will eventually rebound catastrophically on Pakistan itself. The country is threatened by an Islamist insurgency, economic collapse and a massive crisis of governance. Already, the Taliban's [Images] malign influence is spreading unstoppably into society, and into the army and other vital organs of the State. Shielding its supporters in State agencies will undermine the integrity, indeed the viability, of its feeble, near-failing State.

The jihadis have overrun Swat and are going berserk in the frontier and tribal agency areas. As the Lal Masjid episode in Islamabad and the rising incidence of terrorism in Karachi and Lahore [Images] show, Talibanisation could soon devour the Pakistani heartland. This calls for sincere, cold sober reflection and urgent corrective steps. The beginning now made must be sustained.

In contrast to the welcome correction on Pakistan's approach to the Mumbai attacks stands Dr A Q Khan's release from house arrest. The Father of the Pakistani Bomb -- a self-confessed purveyor of nuclear weapons technology, who has probably contributed more to nuclear proliferation than any other individual in the world -- was ordered freed by the Islamabad high court, on the basis of a secret out-of-court deal with the government, which deliberately didn't pursue the strong case it had against him. According to physicist and peace activist A H Nayyar, the deal was brokered by Malik, whom Dr Khan thanked profusely for his release.

This will go down as a foul instance of administrative sabotage and judicial malfeasance. The legality of the Islamabad high court is itself dubious. It was created by General Pervez Musharraf [Images] without constitutional warrant at a counter to the supreme court and the established high courts after the scandalous sacking of chief justice Iftikhar Choudhry.

The government's motive behind reaching the settlement is probably twofold: to resuscitate a national hero in competition with Justice Choudhry, for whose reinstatement Pakistani lawyers are about to launch a mass agitation, and secondly, to gain some cheap and tawdry popularity by claiming that it stands for Pakistan's 'sovereignty' even as American drones continue to pound its territory. But Islamabad should know better. Sovereignty doesn't lie in nuclear weapons or military prowess. It lies in the people and their welfare.

Dr Khan's is a fit case for investigation and prosecution by an international commission under United Nations auspices, similar to the tribunals on Bosnia and Rwanda. After all, he's privy to invaluable information about various shady deals with North Korea, Libya and Iran. The world has every right to know why and through what means these were transacted.

It's hard to believe that Dr Khan set up a nuclear Wal-Mart purely out of personal greed. He couldn't have carried out his illicit activities, including moving huge enrichment centrifuges out of the Kahuta facility, without the army's help. What explains this complicity and its motives?