Does anybody know why poor Zafarullah Jamali was so unceremoniously booted out? More to the point, does anybody care?. Although the indestructible Shujaat Hussain has became the prime minister for the time being, we are told that he is in for a very short ride.

As soon as decently possible, he will relinquish the reins of office to Shaukat Aziz. These arcane moves are especially incomprehensible when it is obvious that it does not really matter who the prime minister is.

As long as General Musharraf is calling the shots as president and army chief, we could have the chowkidar of the National Assembly building designated as PM without the rest of us being aware of any difference in government policies or performance.

But if this is the case, what did poor Jamali do that warranted him being sent back to his comfortable and well-deserved obscurity in Balochistan? After all, he did whatever the 'boss' required of him.

He did not rock the boat in any way, and was careful to avoid the mistake his predecessors made of upsetting the army in any way. Friends who know him well insist that he was so glad at being elevated suddenly above his abilities that he had sworn never to cross Musharaf in any way.

Although the Constitution and the rules of business did not require him to obtain the president's approval for his actions, apparently he would informally run his decisions past the president's secretariat before issuing orders.

But despite being the perfect non-entity for the job, he was also the perfect fall-guy. When things started to unravel in Sindh, the chief minister of that unhappy province was sacked, but as he was a nobody, that wasn't enough. A bigger sacrifice was required, so poor Jamali is back in his village.

Although Shujaat Hussain insists that he is not a 'caretaker prime minister', the fact is that despite being nominal head of the re-united, resurrected Muslim League, he has always been some one the establishment has manipulated.

He has perennially owed his political clout to those who wield real power. When he is told to jump, he does not ask: "Why?" He asks: "How high?" So enter Mr Shaukat Aziz to the roll of drums and a flourish of trumpets.

What are the qualifications of this worthy for the office of prime minster? Clearly, he is a successful banker, and one secret of his success is that he keeps his rich clients happy.

In the current cabinet, he is the minister who most enjoys Musharaf's trust and confidence. Clearly, these are important considerations in what is now a presidential system, whatever the Constitution might say.

In most parliamentary systems, the president is a person who is chosen by the prime minister. Here it is the other way around, and this change reflects the reality of power.

This game of musical chairs underlines the inherent instability of the political system in Pakistan today. Everything is ad hoc, depending on the will of a single individual. And if there are any consultations, they are held among the army corps commanders. Around three years ago, Musharraf was annoyed by some tough questioning at a press conference in New York about the return of democracy, and shot back, in effect: "OK, so you want the facade of democracy? I will give it to you."

In the event, what we have is not even a decent fagade as power remains almost entirely in the army chief's hands. While changing the PM at the drop of a hat is routine stuff, the real problem Musharraf faces comes from the religious alliance under the MMA banner.

The mullahs are sticking to the demand that he retire from the army at the end of the year, as he had promised them to do to secure their vote to legalize his position. Now, he is having second thoughts and is being constantly harried by the MMA at every turn.

One area where these religious leaders are being especially annoying is their opposition to his attempts to defang the armed militants and terrorists who are doing their best to destabilize his government.

Given the ideological and organisational links they have with some religious groups and elements here it is natural that any efforts to stamp out the jihadi movement that has taken roots in Pakistan will cause a backlash.

Many of General Musharraf's problems are of his own creation. Had he not set out to marginalize Nawaz Sharif and Benazir Bhutto by hook or by crook, he would not have created the space for the religious parties to form such a threatening block in and out of parliament.

In these circumstances, who is the prime minister is largely irrelevant. Both in terms of domestic politics and foreign relations, it is Musharraf who is going to take the crucial decisions.

Shaukat Aziz will continue managing the economy, something he has done reasonably well. And given his lack of political support from any quarter except GHQ, he is unlikely to develop any delusions of grandeur.

But for Musharraf, the space to manoeuvre is shrinking. For too long now, he has made liberal noises while seeking the support of religious parties who view him and his American friends with deep suspicion.

His dilemma lies in what to do if he dumps the MMA. Clearly, he needs to line up secular, middle-of-the-road parties and politicians behind his policies which most Pakistanis support. However, to do this, he will have to move out of his rigid mindset and think outside the box.