The Gov't commissioned the Strategic Defence Review in order to find out what duties the Royal Navy would need to perform to secure the Realm, and what resources the Royal Navy would require to achieve this aim.
The SDR concluded that an escort force of 32 escort warships (destroyers, frigates, and potentially cruisers), in addition to the two proposed carriers would be necessary to achieve the desired end.
www.parliament.uk/commons...98-091.pdf
It is worth noting that we are already down to 25 escort warships, so technically the Gov't has already torn up the SDR.
During the Cold War the Royal Navy was configured primarily to contain Soviet Submarines in the Greenland-Iceland-UK Gap in order that the Atlantic shipping lanes could not be closed thereby preventing Operation Reforger from shipping in vast quantities of men and materials from the US to halt a Soviet invasion of Western Europe. Other primary duties included the UK's stategic deterrent, and maintainance of an ability to act globally in support of military operations.
This resulted in a very large number of specialised anti-submarine-warfare frigates (ASW),and a significant number of anti-air-warfare destroyers (AAW), which together could act as mini-flotillas for independent operations around the globe.
Currently, we have a much reduced ASW role resulting from the end of the Soviet naval threat, and a declining number of surface warships resulting from the post Cold-War 'peace-dividend'. The unhappy result of these twin problems is that Britain now has a naval force ill-configured for current duties, and too small to dispatch independent mini-flotillas for global duties.
One possible solution to this twin problem is the re-introduction of the Cruiser class to the Royal Navy, a single vessel that is large enough to provide global reach, and sufficient self-protection from submarine, surface and air threats that it can act independantly of any supporting vessels.
There was such a project under the research & development moniker of; Future Surface Combattant (FSC) which was sadly cancelled in 2004 for 'cost reasons'. I understand that it is being reconsidered for the 2020+ timeframe, arguably far too late.
At the risk of playing fantasy
-fleets I would humbly suggest the folloing force mix of surface warships as eminently achievable, and very sensible in my opinion.
08x T45 AAW Destroyers (start: now)
12x T24 ASW Frigates (start: 2012)
04x T25 C2 Frigates (start: 2014)
08x T65 Global Cruisers (start: 2018)
This would provide the 32 warships required to meet the SDR, and would do so in a flexible manner that would provide proper escorts for large carrier/amphibious task-forces, as well as maintain the Royal Navy's historic global role.
This is not an unachievable goal, in fact it is both eminently achievable and utterly essential. Why then do we pursue this ridiculous notion of an anti-terrorist coastguard?