QUESTION: What's the difference between a "good" Taliban and a "bad" Taliban?

ANSWER: Not much if you happen to be giving the orders on the CIA's programme of targeted drone strikes.

Senior Pakistani militant leader Mullah Nazir, killed on Wednesday when two missiles struck his vehicle in the country's north-west tribal district of South Waziristan, was deemed by some within the Islamabad Government to have fallen into the former, more "benign" category of Taliban commanders.

Put at its simplest, Nazir preferred attacking American, British and Afghan forces in Afghanistan rather than Pakistani soldiers in Pakistan.

Not much of a distinction there you might think, unless of course you happen to be of a certain mindset within Pakistan's intelligence and military establishment who viewed Nazir as a good and useful ally to their own ends in containing Taliban militancy to Afghan soil.

That, however, was not how Nazir's brothers within other sections of the Pakistan Taliban saw him, most notably Hakimullah Mehsud, the overall leader of The Movement of the Taliban in Pakistan (TTP).

Mehsud, it's probably fair to say, regarded Mr Nazir as something of a quisling, or collaborator, and little more than a puppet of the Pakistan Government.

Few intelligence analysts doubt it was this difference in strategy between the two Taliban commanders that in November led to Nazir being the target of a suicide bomb attack while he was in the central bazaar of South Waziristan's main town Wana, close to the Afghan border.

To say that Nazir was lucky to survive that day would be an understatement.

Six people died and 12 more were wounded in the explosion, with Nazir escaping only because he had momentarily left the vehicle to make a phone call.

What immediately followed in the wake of that attack is very revealing in terms of understanding the schisms within the Pakistan Taliban's ranks, its relationship – or not – with the Islamabad Government and the significance of this week's US drone strike killing of Nazir.

To take the first of these factors, it's important to remember that while both Nazir and Mehsud can be called Taliban, they do come from rival clans, the Ahmedzai Wazir and Mehsud clans respectively.

While no group claimed responsibility for the suicide bombing attempt on Nazir in November, barely two days after the attack he ordered all Mehsud tribesmen, who effectively form the nucleus of the TTP, to leave areas under his control.

It was not the first time Nazir has had a run-in with Mehsud or the TTP and doubtless would not have been the last except for Wednesday's US drone fired missiles that killed Nazir, five of his loyalists and two senior deputies, Atta Ullah and Rafey Khan.

While Mehsud and his TTP cadres may be glad to see the back of their rival, there are certainly those within Pakistan's intelligence/military community who will see his passing as problematic.

As far back as 2009, Nazir had struck a non-aggression pact ahead of the Pakistani military's operation against militants in South Waziristan.

Now, because of Wednesday's US drone strike, that pact is in jeopardy and likely to collapse.

All too aware of this, Pakistani security officials were yesterday locked in talks to assess the impact of Nazir's death, with some insisting it would benefit the TTP who are keen to move back into South Waziristan.

One Pakistan official said: "There will be a setback. He was one of those who was keeping his area under effective control and preventing the TTP from operating there. So it will make a difference."

Perhaps the most significant and pressing issue to emerge, however, in the wake of Nazir's killing is what it will do to the already badly strained relations between Islamabad and Washington.

Things in that respect have been bad to say the least, especially following the US Special Forces operation that killed Osama bin Laden on sovereign Pakistan soil, ostensibly without Islamabad's permission.

Saifullah Khan Mehsud, executive director of the prominent Islamabad based think-thank the FATA Research Centre which monitors Pakistan's tribal areas, said: "I don't know what the US was thinking when they decided to hit Mullah Nazir because why would you make things difficult for your most important ally [Pakistan] in the region?

"That would create chaos in that region."

While Mr Khan Mehsud may have a point, it's clearly one Washington appears to be taking little notice of.

Oh to be a fly on the wall at US intelligence briefings of President Barack Obama, as senior CIA and other officials regularly point out that for some time now Pakistan has been far from a transparent or reliable ally. Indeed, more often than not, Islamabad has been more than willing to run with the hare and hunt with the hounds when it comes to dealing with the Taliban on its soil.

Far from being a "good" Taliban, US intelligence officials would point out the same Nazir was close to the al Qaeda-linked Haqqani network, a faction of the Afghan Taliban blamed for some of the most high-profile attacks in Kabul and elsewhere across Afghanistan in recent years.

They would also point out that, in interviews, Nazir said he considered himself to be a member of al Qaeda's global terror organisation willing to provide sanctuary for Afghan Taliban fighters and kill aid workers helping in anti-polio vaccination campaigns ostensibly because they were US "spies".

Controversial – and arguably illegal under international law – as the drone strike programme is, the go ahead to kill Nazir was given.

The fact is Washington has long since tired of Pakistan's ambiguous claims when it comes to dealing with the Taliban.

"Good" Taliban or not, in US eyes Nazir was considered a high value target.

His card was well and truly marked.