Later in his address, Collins says:
It is a big step to take another human life. It is not to be done lightly.
I know of men who have taken life needlessly in other conflicts, I can assure you they live with the mark of Cain upon them.
If someone surrenders to you then remember they have that right in international law and ensure that one day they go home to their family.
and later, this:
If you harm the regiment or its history by over enthusiasm in killing or in cowardice, know it is your family who will suffer.
You will be shunned unless your conduct is of the highest for your deeds will follow you down through history. We will bring shame on neither our uniform or our nation.
This is very much in keeping with Collins' general tone: apparently he doesn't assume that all his men have to do to liberate Iraq is just to kick seven shades of shit out of any Iraqi who gets in their way. It's this that I found most heartening in the address: the fact that, although this war was set in train by bellicose jackasses like Donald Rumsfeld, its conduct is in the hands of men like Collins who are prepared to treat the enemy as more than a few eggs that need to be broken so that we can get on with cooking up the new global omelette.