LONDON, England — In the late 1990s, getting permission to visit former Soviet nuclear sites was relatively easy and after to speaking to scientists still at work in them, the security was rather shocking. But what has alarmed me more over the years was realizing that North American and European research and academic facilities could do with a security audit themselves.

British regulators have routinely outlined security lapses and in the United States nuclear research labs have been penetrated with relative ease by nuclear safety campaigners posing as students. The U.S. Nuclear Regulatory Commission has found that a radioactive source is lost or stolen in the United States almost every day.

In the words of President Barack Obama, "loose nuclear materials could exterminate any city on earth." So the effort to secure those materials needs to be a global one. The U.S.-led megaports system is a frontline defense for a non-proliferation strategy.

The program is seven years old and aims to equip 100 seaports by 2015 so that they can screen ship, rail and truck traffic through monitoring portals looking for radiological and nuclear material.

In one megaport in Antwerp, Belgium, port authorities say they are currently screening about 70 per cent of all traffic, 80 per cent of which ends up on North American soil.

"We seized 50 containers in 2008 with all kinds of nuclear and radioactive sources and that's all kinds of travel coming from all kinds of containers," says Noel Colpin, Director-General of Belgium’s Customs and Excise authority.

None of those incidents posed a serious terror threat but security officials say screening all container cargo is still a key goal.

"I think it’s very important because before we didn't know it, now we can do the screening and we are indeed surprised by the number of seizures and the importance," adds Colpin.

Since 2001, databases kept on behalf of the International Atomic Energy Agency indicate roughly a doubling of illicit trafficking in materials that could be used in dirty bombs using radioactive material or in a few cases for nuclear devices.

One favoured route, through Russia, into Georgia and on to Turkey, means cargo gets an easy ride through to Europe and ports like this one in Belgium. While incidents involving weapons-grade nuclear material are rare, guarding against them is worth doing whatever it takes.

"It’s a game changer, it will change everything we take for granted for a very, very, long time. It’s lives lost, infrastructure damage, counting to billions, but you also have the political fallout, who knows what happens next," says Andreas Persbo, a nuclear researcher with Vertic.

Experts point out, we are still vulnerable, an IND, or Improvised Nuclear Device, could be shielded after being encased in lead and uranium and doesn’t even carry a signature.

"We’re not complete with our mission yet, and we have a ways to go to get to our ultimate goal which is protecting maritime traffic anywhere that it’s going," says William Kilmartin, a program director with the Megaports Program.

And what worries security authorities most is a tangible nexus between arms-dealers, organized crime and terrorists who would seek out insiders from state-sponsored nuclear weapons programs. It’s a deadly combination that experts say could slip through even the best of defenses.

LONDON, England - Wednesday saw no dramatic developments in the investigation but instead witnessed a steady drip of reports and information about what happened and how.

Up to twenty people were arrested but none of the gunmen responsible for the attack were apparently among them. 

Many have commented on the apparent ease with which the gunmen melted away into the city after the attack, and suggested this points to them receiving assistance from rogue elements within the military or the intelligence structure. While there may or may not have been collaboration of this kind, it's a mistake to make this assumption on this piece of evidence alone.

It's easy, for instance, to forget that the men who tried to bomb London on July 21st, 2005 were also able to make good their escape and hide undetected for days. Some of those men, remember, were escaping, unarmed, from busy underground railway stations. It was six days before the Met police had the first would-be bomber under arrest, and detectives in London had all the benefits of the city's massive CCTV infrastructure at their disposal. Lahore, it seems safe to suggest, and notwithstanding the new video out Wednesday evening, is not quite so well endowed with surveillance cameras.

What's more interesting is the number of reports now suggesting that the gunmen were carrying far more arms and ammunition than would be needed to execute an ambush only. Add to that the multiple reports they were also carrying dried fruit, nuts and water bottles in their rucksacks, and it does seem to point towards the possibility they had intended taking the Sri Lankan cricket team hostage. This possible scenario, of course, provides further similarities with the Mumbai attack three months ago.

Perhaps predictably, there have been growing voices blaming India for Tuesday's attack. Hamid Gul, former head of Pakistan's military intelligence agency, has described it as "all too obviously the handiwork of Indian intelligence." Meanwhile, Pakistan's serving Interior Minister, Rehman Malik, has said he does not "rule out a foreign hand." Foreign hand is code for India, of course.

It's not surprising that Pakistan's government might wish to point the finger abroad. At home and around the world, it has been slammed over this security failure. Whether or not individual police officers did their duty on the day – and one can understand why suggestions they did not have hurt when six police were killed in the attack – it doesn't seem unreasonable to suggest that the ruling party's squabble with its political rivals might also have played a part in the failure. 

Last month saw the dismissal of the provincial government in Punjab – of which Lahore is the capital – run by the party of Nawaz Sharif, the main nationwide opposition figure to President Asif Ali Zardari. Along with the outgoing administration, the most senior figures in the province's police force were also removed from their jobs. Faced, then, with a major security challenge – policing an international cricket match – it seems some of the main men responsible were still getting their feet under their new desks.

LONDON, England - It's just hours since the attack in Lahore but on one thing most observers seem clear. The real target of the attack was not the Sri Lankan cricket team, but the Pakistani government. Terror operations like this are aimed at creating maximum international impact, and sport finds itself increasingly in the crosshairs of global terrorism. No sport is more popular in Pakistan than cricket.

A video grab shows a suspected gunman near Gaddafi Stadium in Lahore, Pakistan, Tuesday.

The only reason Sri Lanka were touring Pakistan at all was because the Indian team had pulled out of its planned tour, citing security reasons. After receiving assurances over the team's safety, Sri Lanka stepped in at the last minute. It will surely be the last team to visit the country for the foreseeable future.

That means a loss of prestige and income for Pakistani cricket, and further reinforcement overseas of the idea that Pakistan is not a safe place to visit or to do business. That's just the sort of outcome the attackers will have wanted, and just what the Pakistani government is so desperate to avoid.

The operation certainly appears to have been very well planned, if not, perhaps, entirely well executed, if reports about some of the attackers' weapons failing turn out to be correct.

It seems as though about a dozen gunmen were involved - a large number of people to coordinate in a single operation. The convoy carrying the cricketers was ambushed at a roundabout on its route from the team hotel to the stadium. It was not the opening day of the Test match, but day three - suggesting reconnaissance might have been carried out over the past two days about the route taken by the team bus.

The attackers carried an impressive arsenal of assault rifles, grenades and rocket launchers. "These people were highly trained and highly armed," said the province's governor. "The way they were holding their guns, the way they were taking aim and shooting at the police, it shows they were not ordinary people," he added.

While it appears that that some grenades failed and the rocket launcher failed to hit a target, all of the attackers appear to have escaped successfully after a gunfight with police and security lasting 15 minutes.

So who did it? It seems reasonably safe to rule out the Sri Lankan separatist group, the Liberation Tigers of Tamil Eelam, in this attack. The Tamil Tigers have been engaged in a bloody civil war in the north of Sri Lanka for decades. But it's suffered a series of defeats in recent months at the hands of the Sri Lankan army, and most commentators believe the group just does not have the capability to mount such a complex, well-coordinated attack like this on foreign soil.

Instead, the focus surely falls on one, or perhaps several, of the jihadist-terrorist groups based on Pakistani soil. One such group is the Tehrik-e-Taleban, the Pakistani Taliban movement led by Baitullah Mehsud from the tribal areas in the west of Pakistan. It was blamed for the assassination of Benazir Bhutto in December 2007. And it's been linked with the truck bomb attack on the Marriot hotel in September last year, which killed more than 50 people.

Some initial accounts lend possible support to this being the work of the same group. Lahore's police chief said the men who took part looked like Pashtuns, the ethnic group that hails from the tribal regions close to the Afghan border, the stronghold of al Qaeda and the Taliban.

But some commentators question this. Sajjan Gohel, of the Asia-Pacific Foundation, points out that the Pakistani Taliban, or groups allied to it, have never struck this far from their base in the tribal areas. Taliban-linked attacks also tend to be more rudimentary in nature, and not as sophisticated as Tuesday's ambush, Gohel says.

Certainly, it's striking that this operation was not a suicide bomb attack but one instead carried out by what appear to be highly trained gunmen. It's also perhaps worth noting that they were casually dressed in jeans and jackets. Both these point to similarities with last year's attack in Mumbai, when 10 gunmen laid siege to two hotels and other locations over a period of three days.

That operation has been widely blamed on another jihadist-terrorist organisation, Lashkar-e-Tayyiba (LeT), a group with links to al Qaeda. Unlike the Taliban groups, LeT has its roots not in Afghanistan but in the conflict with India over the disputed region of Kashmir. Even though it would be unusual for LeT to stage an attack within Pakistan, there are good reasons why it may wish to do so now.

Under intense international pressure after the Mumbai attacks, Pakistani officials arrested a series of LeT leaders. Interior Minister Rehman Malik then made the unprecedented move of publicly acknowledging that the Mumbai operation had been in part staged from Pakistan.

Never before had Pakistan made such an admission over an attack in neighboring India, and there are some within Pakistan's military and security apparatus who will not have been pleased to hear it. Many security analysts say those are the people who believe destabilizing India is a strategic objective. They're also the people who in the past helped set up groups like LeT to fight in Kashmir.

Whoever carried out the attack, it certainly represents the most significant challenge to date from within Pakistan to the survival of the civilian government of President Asif Ali Zardari.