White House : Web message shows bin Laden 's isolation . Speaker says global economic crisis is reducing U.S. involvement in the region . Audio message posted on radical Islamist Web says jihad in Gaza 's future . Speaker 's voice was similar to recordings that bin Ali has made in the past .
White House says Web message shows bin Laden 's isolation . Message says global economic crisis is reducing U.S. power in the world . Audio message posted on radical Islamist Web urges jihad in Gaza 's defense . Speaker 's voice was similar to recordings that bin Laden has made in the past .