Why did Israel lose Sinai?
After the 1948 war, in which Egypt used the flat coastal strip from the Suez Canal to El Arish as a main supply route to Arab forces, Israel captured part of northern Sinai, then withdrew under intense pressure from Britain and the United States.
Is West Bank part of Israel?
Presently, most of the West Bank is administered by Israel though 42% of it is under varying degrees of autonomous rule by the Fatah-run Palestinian Authority. The Gaza Strip is currently under the control of Hamas.