Of course you don't have to wait for a Boxer to make the first move. You can initiate an attack if you wish.

After learning how to counter at various points of a Boxer's attack, we proceed to learning to initiate the attack ourselves. It is very important to cover the Boxer adequately as we move in to attack. Repeat: it is very important to cover the Boxer adequately as we move in to attack. If he breaks off from our coverage and strikes us, we can lock both his arms and then strike him.