A victim of a bomb explosion is wheeled out by medics at Moscow's Domodedovo airport after a suicide bomber killed at least 31 people and injured more than 130. (Denis Sinyakov / Reuters / January 24, 2011)
In the United States, such public areas at airports are protected by a hodgepodge of security agencies. In Moscow, visitors are supposed to pass through a metal detector, but one survivor of Monday's attack said he saw no one being required to do so.