This is the first film ever to be shot inside the United Nations Headquarters - locations include the General Assembly and the Security Council, as well as regular corridors and hallways of the complex. The cast and crew filmed on weekends in order not to disrupt the regular work week of the Organization.
Some of the extras in the film (scenes in the General Assembly, the Security Council and in the security camera footage) are actual U.N. staff members, who were allowed to participate after signing the usual waivers. Filming at the United Nations took place over weekends from April - August 2004.
Filming at the United Nations could only take place on the weekends. Film crews would move in on a Friday night, protect and prep the general assembly only to withdraw nearly all of their equipment by Sunday.
Filming was originally scheduled to take place in Toronto. A replica of the U.N. general assembly was underway until it was discovered that it would be very costly to get a manufacturer to make curved fluorescent bulbs in the arched shape of the desks. This contributed to a renewed effort to film at the UN.
The original twist ending involved Silvia Broome having made up the idea of the assassination in order to blackmail a political official from causing genocide in Africa. Although director Sydney Pollack signed on for that draft it was one of the first things he had changed. This in turn changed a lot of the structure of the script so Scott Frank and Steven Zaillian were brought on to doctor it up.
The telephones that appear in various shots of the United Nations building (Control Booth, Security Checkpoint, etc) are ITE-12S and ITS-12SD phones, used with the EADS Telecom PointSpan telephone system (and really used by the U.N. - EADS Telecom cites "The United Nations" as a customer).
The American poster design has the flags in front of the U.N. building curved across the bottom. On the first version of the poster, the one on the far left was the U.N. flag. This placed the U.N. flag higher on the poster than the adjacent American flag, which is exactly in line with the flag etiquette in force at U.N. Headquarters. However, the poster was redesigned, presumably to avoid causing offense to American audiences who might be ignorant of the U.N. HQ flag etiquette. The second poster removes the U.N. flag entirely, and moves every other flag one flagpole over, so that the American flag is now highest, followed by the Canadian, then the British which, incidentally, is still incorrect on several counts: at U.N. HQ the US flag does not fly higher than the others since it is contrary to international flag etiquette for one nation's flag to be displayed higher than any other in time of peace, and the flags at the U.N. are arranged in English alphabetical order.
When Catherine Keener gets on the helicopter around 25 minutes into the movie she receives a phone call. The voice on the phone is supposed to be speaking an African language. It is actually speaking Hebrew. It is the message one gets when one dials a non-existent number in Israel.
The scene shot in the Security Council room was shot in one day. That room is on call 24/7 for emergency meetings. If one were to be called, the crew would have three hours to clear out before the meeting.
The setting of the film inside the UN itself was the big attraction for Sydney Pollack though he didn't like the plot in the first draft of the screenplay. This was substantially altered through rewrites.