Unsurprisingly for a country which came into being in 1947 with a relatively immature political structure and without a constitution, military coups in Pakistan have been disturbingly frequent in its short history.
Four civilian governments have been overthrown by the military since the country's independence from Britain in 1947. The army was at it again on Saturday declaring a state of emergency, dismissing most of the Supreme Court, cutting communications, and deploying troops throughout the capital. This time, however, the military was not dismissing a popularly elected government but shoring up a regime that has been seriously weakened by internal dissent and opposition, and is under considerable pressure from the United States (its No1 ally and aid donor) to do more to promote democracy.
Even before he sacked Pakistan's Chief Justice, Iftikhar Chaudhry, last March for insisting on an investigation into alleged government human rights abuses in Baluchistan, President Pervez Musharraf's popularity among secular Pakistanis was waning the result not just of failed promises to restore genuine democracy but of clumsy attempts to secure another term as president without the inconvenience of free and fair elections.
Musharraf's support for America's war on terror has brought him serious problems in Pakistan's tribal regions, too, where sympathy for the Taliban, and hatred of all things American, is strong. The regime's appeasement of Islamic fundamentalists has also been a disaster, and has only encouraged attempts by militants to extend sharia law over towns and regions. It has also led to video and CD stores being blown up, and girls' schools being bombed.
Islamic militants used to be confined to the tribal areas lining the frontier with Afghanistan, but have now spread to the larger cities. Recently, a pro-Taliban cleric, Maulana Fazlullah, and a follower virtually took control of the Swat Valley, vowing to further spread fundamentalist Islam.
The reluctance of Pakistan's security forces to act, whether out of fear of or sympathy for the Taliban and religious fundamentalists, has led to a rising incidence of suicide attacks in cities like Rawalpindi.
It's likely the worsening atmosphere of fear and uncertainty was one reason behind Musharraf's declaration of martial law on Saturday. The more immediate rationale was that the Supreme Court was on the verge of declaring illegal Musharraf's re-election by the National Assembly last month. Under Pakistan's constitution, no-one can combine the offices of president and army chief, and though Musharraf had promised to resign as commander of the army by November15, he clearly felt the judiciary could no longer be cowed, especially after the reinstatement of Chaudhry in July.
Now Chaudhry has been sacked again, along with most of his colleagues, because in the words of the Government's official proclamation of emergency, "some judges by overstepping the limits of judicial authority have taken over the executive and legislative functions".
One suggestion is that Musharraf will appoint a new bench more sympathetic to his point of view, and that the state of emergency might be over relatively quickly. But his actions have dealt a serious blow to the US-backed "transition to democracy" an agreement allowing former Prime Minister Benazir Bhutto and her Pakistan People's Party to contest parliamentary elections in January in return for Bhutto withdrawing her objections to Musharraf's re-election as president.
Bhutto's narrow escape from a suicide bombing that killed 136 people and injured more than 500 was a reminder of the violence and intimidation that now characterises Pakistani politics. If Musharraf is to head off popular unrest for this coup, he will need Bhutto's help. So far, she has refrained from calling her supporters on the streets, but any delay in the general election scheduled for January puts this support at risk. In any event, Musharraf's unpopularity, his judicial meddling, and the decision to detain lawyers, civil rights activist and journalists, is likely to result in a wave of protests, with a good chance that demonstrators will clash with security forces.
If declaring emergency law ultimately legitimises Musharraf's presidency, it also risks bolstering Islamic fundamentalism and giving the militants fresh ammunition with which to challenge the Government's authority. Possibly, Musharraf has already calculated this risk and determined that it is an acceptable one because Western governments, and the US in particular, are likely to overlook the coup (and, indeed, support it implicitly) out of fear that Islamic extremism is spreading in south Asia and that firm action is required to contain it.
Musharraf's strategy depends on the loyalty of the military, but that loyalty may be tested if the emergency drags on and civil disturbances increase. The army is more politicised, and split on factional lines, than ever, and an internal revolt is not out of the question.