Not good at all. Does your employer provide armed security for you and appropriate transport, secure accommodation. Where will you be working. If you are working on an American base it will be secure.
Well if you are working for American company Im sure security is number one for them ,for their employees and im sure you would stay from base or camp.
If you mean travelling by road then it is unsafe. Even if accompanied by security there is every chance of being attacked. The whole of Afghanistan is not a safe country for °µÍø½ûÇøs.