I just saw an interesting article by the English mediator Neil Denny in which at one point he discussed the difference between assertiveness and aggression. As he put it:
Being assertive does not mean locking horns or getting into a fight with the client. That is aggression. Assertiveness simply means communicating your own needs, wants and beliefs in ways that do not impact those of the other person.
Many people say they want an aggressive attorney, but is what they want someone who will get into fights, someone who is going to alienate the court and the other side, making getting to settlement more difficult? Certainly there are some clients who just want to make life miserable for the other party, but I don’t find that the majority of clients are looking for that at all.
I believe that far more often they are looking for an attorney who can be assertive on their behalf. They are not looking to start a fight, but to have their interests and needs heard. The role of the attorney then is to to help the client assert themselves, to make sure they are heard by the court and the opposing party, so that their interests are fully considered and factored into any final result.
Aggression can actually work against accomplishing that. Aggression makes others defensive, causing them to be less willing to listen to what you have to say or cooperate with you.
Assertiveness works the opposite way. It involves working with the other side to move towards solutions, and letting the other side know how they can best work with you to achieve something that is satisfactory for both sides.
Aggression creates problems, assertiveness solves problems.