Hammerhead Six was born out of necessity. When we completed our UW experiment in the Pech Valley in 2004, we understood the team replacing us and other teams in Afghanistan were going to replicate the model we had proven. It became apparent years later, that not only was it not replicated, but the lessons we had learned the hard way had been lost at a high cost. I felt obligated to put the lessons to paper for those that could benefit from our “education” in the Pech Valley.