THE simmering civil unrest that boiled over this weekend into lethal exchanges of gunfire between rival political factions in Karachi, Pakistan's biggest city, are indicators of a deeper malaise that threatens not only the increasingly fragile rule of President Pervez Musharraf, but also the stability of the entire region and the security of the wider world.

The flashpoint was the dismissal of Iftikhar Chaudhry, the country's independent-minded chief justice, because of his outspoken criticism of Musharraf's bid for a third - unconstitutional - term in office. However, the real issue is growing popular disquiet over the President's perceived unconditional support for the US-led "war on terror" and its impact on what most in Pakistan see as their fellow Muslims in Iraq and, more importantly, in neighbouring Afghanistan. A third, constitutionally engineered term as leader of the world's only nuclear-armed Islamic state is regarded by a growing number of voters as a term too many.

The dispatch of Pakistani troops to clear pockets of al Qaeda fugitives from the tribal lands along the Afghan-Pakistan border at the bidding of the White House was highly unpopular. More than 800 of Islamabad's soldiers returned in bodybags before a tenuous peace was brokered last year, which left tribal leaders still firmly in control of vast swaths of remote territory in exchange for public agreement not to grant traditional Pashtun hospitality to terrorist "guests" from Saudi Arabia, Chechnya and North Africa. The area remains, however, a safe haven for a resurgent Taliban, offering sanctuary for wounded fighters, training areas for would-be mujahideen, and a logistical springboard for attacks against British and Canadian soldiers in Helmand and Kandahar. Even Musharraf baulked at inviting the backlash that would have accompanied further military incursion, or meddling with the wide and deep-seated religious support for the militants. That apart, it suits Islamabad to undermine the Karzai government in Kabul and to keep a hand in the Great Game next door. Channelling holy warriors away from potential armed involvement in Pakistan's domestic affairs is a bonus.

The suspicion of informed observers is that the current crisis and its accompanying street violence may have been provoked deliberately by Musharraf to allow him to declare martial law and thus legitimately delay any parliamentary vote on his third term in office. Under Pakistan's constitution, he would be barred from seeking such office later this year after serving two terms since he seized power in 1999 in a bloodless coup. He is also chief of the army, and it is on their bayonets that his precarious throne is balanced. If the constitutional confrontation is being stage-managed, there is the danger that it could spiral out of control and that the deeper tensions over fundamental Islamic issues and international alliances might erupt.

Worse, from a Western viewpoint, is that a successful Islamic movement might be swept into office and gain control of scores of nuclear warheads and missiles, with potentially catastrophic consequences. Musharraf is sitting on a powder keg which could damage everyone, and the West must not underestimate the significance of his situation.