You can hardly expect the RBL to be anti-war, basically it's a welfare organisation for ex-members of the military. It remembers the First World War because that was the spur to its formation and much of its resources have been used supporting those who fought in it as well as those who served later. It is neither for nor against the wars but for the well-being of its members.

And it is a difficult situation. Imagine that you were in a Syrian town being attacked by ISIS and that you are aware that if the town falls the men will be slaughtered, the children taken away to be brought up by the ISIS fighters and the women sold into slavery, would you take a gun and fight if you were offered the chance or would you surrender and take the consequences?