Marked "Secret UK Eyes A'" and entitled Re-instatement of President Makarios in Cyprus by means of British military support, the document warns of the dangers involved in such an operation.
"This paper considers the general forces level necessary to achieve this," it begins. "It does not address itself to the possibility [of intervention] by Greece, Turkey or another nation ... However, the attempted intervention by air or sea of Greek forces could be deterred by our own forces given about 10 days notice.
"The threat will not only consist of the Cyprus national guard, Greek national contingent, EOKA B [paramilitary Greek loyalists] ... there will be sizeable elements who will actively oppose us by resorting to guerrilla warfare."
The total strength of "Greek loyal forces" was estimated at 55,000, but "standards of training are poor".
The assessment concluded that three brigades - as many as 15,000 soldiers - would be needed.
Close air support would also be necessary, but added: "Bitter experience has shown us that even a small number of dedicated men from the local population can pin down an inordinately large force for an indefinite period and we might well end up by facing an open-ended and expensive situation, like in Northern Ireland.
"Our chances of ever fully subduing the island as a whole ... must be extremely low."
Up to 23,000 service families, UK citizens and friendly nationals would be vulnerable to hostage-taking but evacuating them before an intervention "would make our intentions plain", it said.
The government hesitated and events moved faster than anticipated.
http://www.guardian.co.uk/uk/2005/jan/0 ... larchives1
