P&Y: "Difficult to explain to many who don't know soccer that when your team HAS the ball, they are all a part of the offense; when your teams doesn't have the ball, they are all the defense. . ."

I strongly agree with your statement. I have always told my teams that, when the opponents have the ball, we have 11 defenders. When we have the ball, we have 11 attackers.

This is why, as a coach, I have usually refrained from using the term "defender" as one of the positions in our fomation. I prefer to use the term "back".