OK here's a thought which the crewroom lawyers might like to argue around.
The original invasion of Iraq may or may not have been illegal.
However - we are no longer at 'war' as we are now in support of the recognisied Iraqi administration.
The MO has been given an order to deploy and administer medical services to British Servicemen - he is not prosecuting a war of any kind - legal or illegal.
Therefore the order to deploy is legal and must be complied with.
Points! questions?
And for the record: Trench dodging is trench dodging no matter how many lawyers you have on your side.