Memo: Green Zone housing facilities vulnerable to attack.

The Green Zone “was once considered an American oasis — a protected bubble of comfort food, large, American-made sport-utility vehicles and enforced speed limits.” Yet a day before Amb. Ryan Crocker and Gen. David Petraeus were set to testify to Congress about progress in Iraq, the U.S. embassy yesterday sent a memo to employees forbidding them “from sleeping in trailers or from spending long periods of time in them this Wednesday and Thursday.” In the past two weeks, four Americans have died from shelling attacks in the Green Zone.