FILE - In this Thursday, Nov. 29, 2012 file photo, destroyed buildings, including Dar Al-Shifa hospital, bottom, are seen after airstrikes targeted the area last week in Aleppo, Syria.

 

              FILE - In this Thursday, Nov. 29, 2012 file photo, destroyed buildings, including Dar Al-Shifa hospital, bottom, are seen after airstrikes targeted the area last week in Aleppo, Syria.
FILE - In this Thursday, Nov. 29, 2012 file photo, destroyed buildings, including Dar Al-Shifa hospital, bottom, are seen after airstrikes targeted the area last week in Aleppo, Syria. President Bashar Assad has exploited his greatest advantage on the battlefield _ his air power _ to push back rebel advances and prevent the opposition from setting up a rival government in its northern stronghold. Along the way, fighter jets and helicopters bombed bakeries, makeshift hospitals and residential areas, according to a new report by a U.S.-based rights group released Thursday, April 11, 2013 accusing the regime of committing war crimes with indiscriminate airstrikes that have killed more than 4000 since summer. (AP Photo/Narciso Contreras, File)