I don't see what Republicans would have to gain from this, be them dissident or not. With a scaling down and exit of operations there I can't see why anyone would want to rekindle or perpetuate the military involement there. If you're asking for theories then I'd be looking to people who are the most uncomfortable with the new peace and wanting to give reason to keep British troops over there. Relations have progressed massively there and it would be a shame for a minority to bring back a level of mistrust that has been so hard fought to overcome. 
