Diplomatic couriers travel first class and are the first to board when bearing a diplomatic pouch and the first to deplane upon arrival to keep an eye on any larger diplomatic pouches in the belly of an aircraft. They monitor when the hold is secured -- and when it is reopened -- to ensure thieves don't attempt to grab the sensitive material or spies don’t try to clandestinely examine the contents of the pouch in what's known as a "black bag" job. They also travel under black diplomatic passports, ensuring smooth and uninterrupted travel. But unlike Hollywood’s depiction of diplomatic couriers -- with black briefcases handcuffed to wrists -- the average air traveler would never be able to spot a courier in transit. In many cases, they keep their bright orange diplomatic pouch inside a normal carry-on bag, stuffed under the seat. The most important aspect of a courier's job is...