Gen. David H. Petraeus, the top American commander in the Mideast, appeared to faint while testifying before the U.S. Senate on Tuesday. While being questioned by Sen. John McCain (R-Ariz.), Petraeus slumped over, looked dazed and was assisted by aides who rushed to his side. A few seconds later, he quickly sat upright again and then left the room on his own power. After being examined by a doctor and eating some food, Petraeus returned to the Senate Armed Services Committee hearing room 20 minutes later, smiling. A spokesman said Petraeus was dehydrated and became a bit lightheaded. He had been travelling recently and was jet-lagged, the spokesman said.