Found this link which raises some interesting questions with regards to the use of armed MEDEVAC and the Geneva Convention. It would appear that in order to 'comply' with the Geneva Convention, US Army MEDEVAC "Dustoffs' display the Red Cross and are unarmed, thus requiring an armed escort. This therefore implies, from a US Army perspective, that other nations (including the UK) who fly unmarked, armed MEDEVAC missions are not complying. Whilst obviously an issue of 'interpretation' it will be interesting to see if the US Army adjusts its CONOPs as a result of the letter.
http://www.michaelyon-online.com/ima...01-17-2012.pdf
It also appears to raise the interesting question that if our adversaries do not recognise the Geneva Convention then why should we be 'shackled' by certain aspects of it.