Today's suicide bombing of a terminal at Moscow's international airport reminds us that terminals remain "top of mind" as a terrorist target.

A recent suicide bombing of a major terminal includes June 2007 at Glasgow International Airport, when a Jeep Cherokee, laden with explosives, was driven into the terminal by terrorists.

Also, let us not forget al-qaeda's thwarted plan to blow up the international terminal at LAX on New Year's Eve 1999 using a suicide car bomb.