By Syed Shoaib Hasan
BBC News, Islamabad
Mr Khan's arrest is bound to lower Taliban morale
The arrest of Muslim Khan is not a turning point in the context of the army operation in Pakistan's troubled Swat district.
But it still holds great significance, given the fact that recent events had catapulted him into the top ranks of the Taliban leadership in Pakistan.
The spokesman for the Taliban in Swat, he was taken into custody by the army late on Thursday night in the war-torn valley.
Pakistan army spokesman Maj Gen Athar Abbas told the BBC he was one of five Taliban commanders arrested in a raid.
He denied local reports that the men had been lured under the guise of talks and then taken into custody.
Whatever the circumstances, Muslim Khan's arrest is another crippling blow for the the Taliban in Swat and will inevitably result in a further loss of morale.
The militants are under pressure from local militias and the army
At the moment the Taliban are on the run, with much of their top leadership either in custody or dead.
This is said to include the head of the Taliban in Swat, Maulana Fazlullah.
The army said in July that it believed he was seriously injured in an airstrike and "near death".
Muslim Khan was quick to deny this, calling it "government propaganda". Later, he called newsmen and played a recorded message from Maulana Fazlullah saying he was alive and well.
But reports have continued to abound about his death and at the very least the pressure from the army has effectively made him incommunicado.
Because of this, Muslim Khan had emerged as the voice of the Taliban in Swat.
With the army having won the battle on the ground, Mr Khan kept the Taliban's morale from shattering completely.
He issued frequent statements denying army claims that the Taliban had left Swat.
The Taliban had only "withdrawn" from Swat's urban areas, he said, and the battle was still on in the mountains and fields.
While initially this was seen as an apt description of what was to come, the army's bludgeoning advance put paid to any semblance of resistance.
Place of fear
The Taliban fled in some places and were killed in others.
The army says that it now controls the Swat valley
The military took firm control of what had - a few months ago - justly been seen as a Taliban emirate.
To the surprise of many of its critics, the government was able to say it was in control of the Swat valley within three months of the army operation.
In July, Pakistan's Prime Minster Yousuf Raza Gilani declared that it was now safe for the hundreds of thousands of people who fled the fighting to return home.
For those who initially choose to take up the challenge, the valley remained a place of fear.
Most of the region remained lined with checkpoints. The army continued to heavily patrol the region and regularly ran into ambushes by the militants.
Muslim Khan would make his presence felt at such times, talking up Taliban attacks and arguing that they would soon re-group and take back the region.
This, however, was not his only role. Mr Khan also acted as the main liaison point with other Taliban groups across the country.
In a conversation released a few months ago he can be heard berating an unnamed Taliban commander in Waziristan for not coming to the aid of the Swat militants.
He can be heard calling for indiscriminate attacks across the country at the height of the army operation in Swat.
Recently Mr Khan was even briefly named as spokesman for the Pakistan Taliban following the death of Baitullah Mehsud.
But this came as the power of the Taliban was all but wiped out in Swat.
Muslim Khan's presence on the airwaves, however, was one reason the army stopped short of declaring total victory.
His arrest is therefore a major milestone in the government's efforts to deny militants the oxygen of publicity. He was one of the few leaders who could speak English fluently.
The militants are on the run from the army and have also been recently hounded by local tribal militias.
Thus, in many ways, Muslim Khan's arrest comes during what many here are calling the Taliban's "darkest hour".
Militant activity across the country is at an all-time low, with no significant attacks outside the North West Frontier Province since July 2009.
It is also a great and rare moment of success for the Pakistan army.
Much maligned in its previous efforts to curtail the militants, it is now savouring the moment.
But analysts warn that the army needs to continue the campaign into other Taliban strongholds if this is a victory that can be successfully built upon.