The reporter who comes to Karachi, Pakistan is given certain cautions.

Do not take a taxi from the airport; arrange for the hotel to send a car and confirm the driver's identity before getting in.

Do not stay in a room that faces the street.

Do not interview sources over the phone.

Do not discuss subjects such as Islam or the Pakistani nuclear program in the presence of hotel staff.

Do not leave notes or tape recordings in your room.

Do not discard work papers in the waste basket; flush them down the toilet.

Do not use public transportation or accept rides from strangers.

Do not go into markets, movie theaters, parks, or crowds.

Do not go anywhere without telling a trustworthy someone the destination and expected time of return.

And, above all, do not go alone. Ever.

The Marriott in Karachi satisfies lodging guidelines. Metal detectors flank the entrances, guards with sawed-off shotguns patrol the premises, and the shopping arcade leads directly to the U.S. Consulate — which seemed a plus until a car bomb killed 12 people there on June 14. My room, per instruction, is on the Marriott's backside, and offers a fine view of the nearby Sheraton, where a bus containing 11 French nationals was blown up by a suicide bomber in May.

It is also where, according to a U.S. official, F.B.I. agents recovered a videotape showing an American journalist having his head cut off. His name was Daniel Pearl, he was 38 years old, a father-to-be, and South Asia bureau chief for The Wall Street Journal. He got the same security briefing I did...