The attacker at the Pakistan International Church arrived here Sunday dressed like many of the other worshipers. He was cleanshaven, and he wore a Western-style shirt, pants, and jacket rather than the traditional Pakistani garb known as salwar kameez. But in his jacket, police say, hid the grenades that injured more than 40 people, and killed five.
Police now say the tactics of the attacker show that this was not simply an attack on Christians there are easier churches to target. Rather, this church was chosen for its proximity to the US Embassy and for its high percentage of foreign attendees, investigators say.
Like the kidnapping and execution of American journalist Daniel Pearl, analysts say, this attack is part of an emerging strategy of reprisals by Islamic militants to punish America for its war on terrorism and to destabilize the pro-US government of President Pervez Musharraf.
"It was not Christians but Americans who were the target," says Shahidur Rehman, a political analyst in Islamabad and author of the book "Who Owns Pakistan?" "There are many larger Christian churches that have no security."
To get to the church, the attacker would have had to either evade or talk his way through two separate police checkpoints.
It is this sophistication, and the possibility that the attacker ended up killing himself to increase the death count, that is leading investigators to suspect groups that have ties with Al Qaeda, the terrorist organization run by Saudi dissident Osama bin Laden.
Observers say the attack along with the Daniel Pearl kidnapping could be an attempt to show Musharraf's inability to bring Islamic militancy under control. Others say that America has no choice but to support Musharraf.
"If Musharraf dies, that's it, there's no No. 2," says Ardeshir Cowasjee, a columnist for Dawn, a leading Pakistani newspaper. "The support Pakistan is receiving is not enough. If killing one Taliban takes $1 million, then at least you can wipe out our debt."
At press time, only four bodies had been identified including two Barbara Green and her daughter, Kristen, who are the wife and daughter of a US diplomat. The fifth body has not been claimed or identified, and Pakistani police who welcomed the arrival of FBI investigators this week say they believe this body, identified by eyewitnesses as a young Afghan or Pakistani man, is the missing assailant.
Musharraf's adminstration recognizes that its crackdown on Islamic militant groups is creating tensions here.
"A backlash or a violent reaction in certain areas was expected," says Lt. Gen. Rashid Qureishi, spokesman for Musharraf, adding that the "majority of Pakistanis believe in freedom of expression" and Musharraf's policies.
"Whether this [attack] was against Americans or foreigners in general, or on non-Muslims, is hard to say.... But there are those elements who would like to destabilize Pakistan because of its support of the war in Afghanistan."
One of the central dilemmas now for Musharraf, who came to power in 1999 in a bloodless coup, is whether to continue this crackdown in a bid for law and order, or to let some steam out of the political pressure cooker by abiding by his nation's Constitution and lifting political constraints ahead of elections this October.
His choice is not an easy one. If Musharraf allows the law-and-order situation to deteriorate further, he will lose the interest of foreign investors who can create jobs, and the confidence of allies such as the US.
Even after numerous presidential speeches to the nation, anti-American sentiment continues to linger although with top religious and militant leaders, this sentiment has been muted. A separate and annual dispute between two rival Muslim sects, Sunnis and Shiites, has threatened to destabilize Pakistan even more, as sporadic murders from Karachi to Islamabad have led to 70 deaths thus far.
Yet, if Musharraf continues his ban on political activity, begun after Sept. 11, he could be labeled as just another military despot. This week, former Prime Minister Benazir Bhutto pledged to stay out of next fall's elections if Musharraf promises to step down as president.
Other mainstream parties are planning a rally Saturday just to call for the right to hold public assemblies, a crucial campaign tool for the planned Oct. 12 elections.
"The most important question is whether Musharraf holds elections in October," says Mr. Rehman. "If he holds elections, he has to allow political activity, and then the jihadi [militant] and sectarian groups will get involved too."
But in Islamabad, the Musharraf regime is hoping to restore confidence in other ways. Yesterday, he announced that the heads of Islamabad's police agencies would be replaced because of "lapses" in security, which allowed the church attacker into the diplomatic enclave, one of the most heavily guarded sections of the nation's capital.
Police also began a major crackdown on illegal immigrants yesterday, as part of new measures introduced in the wake of Sunday's attack.
Afghan, Iranian, Iraqi, and Somali nationals were among 30 people detained in overnight raids around the capital as police conducted visa and identity checks, reports Agence France-Presse.
Meanwhile, the government is reportedly seeking to expel thousands of Arabs, North Africans, and Afghans from its thousands of religious schools, or madrassas.
The US State Department renewed a worldwide caution to Americans, saying the Islamabad attack indicated that terrorists might be seeking softer US targets. Dependants of US Embassy personnel in Pakistani cities have been authorised to leave the country voluntarily.