The CEA is not just a MOD allowance.......... The FCO and other Govt Depts also make good use of the 'perk'; therefore, it would be interesting to see if HMT scrap it for their brothers in arms????
Another issue would be the pool of volunteers that would come forward for the few overseas postings still available. My understanding is that they (Manning) struggle now to get the right level of experience for the posts, so with the removal of CEA that pool of manpower would reduce still further.