Mary Thornberry never thought this day would come. But she has decided she can no longer stay in Egypt—the country she has loved and chosen to live in for nearly two decades, through revolts, protests and the political uprising that swept President Hosni Mubarak out and Mohamed Morsi into power. “In sorrow and anguish, I shake the Egyptian sands from my sandals and return home,” Thornberry, a former Fort Worth resident, told the Star-Telegram in a recent email. “This is forever. Irrevocably.” She made the decision as the number of deaths and injuries rises in the midst of clashes between...