This is the schtick to defend others.
You are a trained bodyguard, and can instinctively react to threats to other people. When somebody close to you is attacked, you can either grab them and take cover or give covering fire in such a way that they benefit from your immense experience. In effect, you can do an ActiveDefense for another as a simple 1-shot action. You can choose whether you want to interpose yourself when defending others, but it is still a 1-shot action in either case.