The texts became public after a drawn fourth Test in Leeds where Pietersen scored a superb 149 only to say it was "hard being me" in the England dressing room, with the fall-out seeing the gifted shotmaker dropped from the team that played the final Test against the Proteas.
Strauss, recalling his feelings, wrote: "The England cricket team are in crisis again. Coach Andy Flower and I have found ourselves in the middle of a destabilising and potentially damaging PR game between Kevin Pietersen, the England cricket team and the ECB (England and Wales Cricket Board).