Prime Minister Nawaz Sharif's move to use the army and set up military courts in Karachi to combat crime and terrorism has drawn mixed reactions.

Most of the opposition politicians including Benazir Bhutto and the MQM (Muttahida Qaumi Movement) leader, Altaf Hussain, have condemned the move, and have described it as an attempt to undermine democracy.

But the action has been welcomed by several government politicians who believe this is the only way to solve Karachi's chronic law and order problem.

Karachi has been the Achilles heel of successive Pakistani Governments.

Whether the state of extreme lawlessness is ignored, or whether action is taken, there is always an outcry.

Sharif: Hopes constitution will solve the crisis

Prime Minister Nawaz Sharif is facing the same dilemma.

His latest decision to call on the army for help and to set up special military courts to try alleged terrorists and criminals is a controversial but bold move.

It also shows his growing frustration in trying to find a solution to what has largely been described as a politically-motivated crime situation.

Mr Sharif is confident that once a system of speedy military justice is put into place, with cases completed in less than 10 days, the situation is bound to improve.

To some extent this is true.

Past experience not encouraging

From the army's point of view the biggest flaw in the 1992 military crackdown in Karachi was that it was never given the power to prosecute the alleged culprits.

Thousands of people were arrested during the operation but most of them were later released by the civilian courts.

A similar situation was faced by Benazir Bhutto's government in 1995 when her interior minister, Naseerullah Babar, used the police and paramilitary Rangers against the alleged terrorists.

This time, however, fewer cases were sent to the civilian courts.

Instead, the authorities allegedly indulged in large-scale "extra-judicial" killings of those arrested for such crimes.

On both occasions, the action provided a brief respite from violence.

But soon Karachi again plunged into widespread cases of sniper shootings and politically motivated murders.

Benazir Bhutto: Among those criticising military courts

Now another serious attempt is being made to wipe out crime and terrorism in the city.

For the first time Article 245 of the constitution has been invoked to give extraordinary powers to the army to deal with the Karachi situation.

It may be said that with such powers to arrest and prosecute criminals the army would have no excuse for failure.

But because of the complications of the unique Karachi situation many political observers have already raised doubts about the success of this latest move.

Karachi's wave of violence is now in its 14th year. Thousands of people have died.

A thin dividing line

But what has made the restoration of peace almost impossible is the fact that here a very thin line divides crime from politics.

Clearing up after a police raid

So whenever there is an action against the alleged militants, one or the other political groups - from the mainstream MQM to its Haqiqi faction - comes to their rescue by accusing the authorities of victimisation.

Mr Sharif believes that if some of the culprits are given jail terms through this system of military justice, things will improve in Karachi.

But the real task before the authorities is to round up the armed militants - most of whom have already gone into hiding.

Prosecution in military courts will come later.

Although the military command has learnt from past experience in Karachi, many analysts believe the army are still not trained to combat urban terrorism, and may find it extremely hard to catch armed men belonging to the various militant groups.

In such a situation any wrong move, like arresting the innocent supporters of any group or relatives of the accused - something not uncommon in Pakistan - may have a serious backlash.