The United States and its allies are weighing the possibility that Syrian President Bashar al-Assad, under growing military pressure, may soon narrow his focus on defense of more limited areas of the country, the top U.S. general said on Wednesday.

Losses in the north, east and south have put Assad under more military strain than at any point in the four-year-old war, which has killed more than 200,000 people and displaced millions, according to United Nations data.

General Martin Dempsey, chairman of the Joint Chiefs of Staff, told Congress that his trip to Israel last week was focused on discussing scenarios involving Assad’s departure or his government’s collapse. […]