Inside Story - Buffer or barrier to Egypt-Gaza relations?

Egypt plans to double the size of a buffer zone along its border with the Gaza Strip. The government says the measure is intended to put an end to the movement of armed fighters and weapons from Gaza to Egypt's Sinai Peninsula. The first phase of the operation began in October, days after 30 Egyptian soldiers were killed in a suicide attack on a checkpoint close to the Gaza border. Thousands of people in northern Sinai were ordered to move out. Their homes were then bulldozed and bombed. The buffer zone runs for about 13 kilometres along Egypt's border with the Gaza Strip. The first phase cleared an area 500 metres wide, destroying homes - and tunnels used for smuggling. The security buffer is now being extended, to one kilometre. But is Egypt's overriding justification one of national security? Or are there regional and international pressures at play?