Afghanistan being a war zone has very few places that could be called safe havens for º£½ÇÂÒÂ×s. In my experience, the best city to live in Afghanistan is its capital city Kabul.
Being the capital of the country the city has lots of security personnel on ground that try to keep mishaps at bay, however the safest options to stay are the company compounds. Kabul used to have good number of expats however it has declined a lot since the departure of foreign troops. It is a very beautiful city with extreme climates in winter and summer. As an expat one can expect to find every kind of food or groceries in few of the stores located in Shahr E Naw area.
Other good options include Mazhar E Sharif and Herat, however both of these cities do not host much of the expatriate community and are not connected internationally. However, I would personally recommend that one (if situation allows) should visit both these cities as they are rich in history and Afghan culture.