Al Qaeda must be gearing up for another attack.
In terms of the embassy staff, it is a fairly common occurrence for dependents and non-essential personnel to be evacuated for a certain period of time. During Desert Storm, 32 embassies had dependents and non-essential personnel evacuated. Our embassy in Jakarta is under the same conditions now.
Non-essential personnel are designated by the embassy. Essential personnel are deemed critical to the basic operation of the mission. Everyone else is non-essential. Usually, about one-half to two-thirds of the personnel are non-essential. They come mostly from the non-State agencies as well as junior personnel from State.
There are several types of evacuations for embassy personnel, authorized (voluntary), and mandatory. This is a mandatory draw down. Warnings and advisories are issued to the general public, which is a different kettle of fish.