Top Russian Official: Plane Terror Likely MOSCOW - A top Russian official acknowledged Thursday what many citizens already suspected - that terrorism was the most likely cause of two jetliners crashing minutes apart, a feeling reflected in a newspaper headline warning that "Russia now has a Sept. 11."   A day after officials stressed there were many possibilities besides terrorism, presidential envoy Vladimir Yakovlev told Russia's ITAR-Tass news agency that the main theory "all the same remains terrorism."   Yakovlev said the planes' flight recorders provide no clues to the disaster...