As far as I know since I joined while Madina was basically already dead, Madina was only allied with 1 member of the moot, not a member of the moot and I thought I heard a good reason of why they didn't help Madina but I don't remember. For the Barcan war, I will not comment on whether or not they will be helping as I am not the leadership of Terran or D'hara so I don't know what they are planning though if they don't ever help in the war then I could see how you are calling them dishonourable cowards.
If they were honourable and not cowards, there participation wuoldn't even be in question