Lets go through each of these in turn shall we :
- Type 45 - either built or in building. Their predecessors are now over 30 years old and expensive to maintain. Why would you cut T45? Save a few billion, and what would provide air cover for your naval assets then?
- Carriers - there may be a issue with building 2 carriers of this size but there is a lot of pork at stake here.
- JSF - without JSF your carriers are meaningless, unless you plan to operate Lynx with Amraam or something like that. BAE are heavily involved in building these = jobs.
- Astute SSN - as with the T45 they are replacing ageing submarines. SSNs are probably the most cost effective and reliable method of first phase power projection, especially when fitted with Tomahawk or similar missile.
- Trident - the argument goes on. I don't really like Trident but there isn't a cheaper alternative that guarantees nuclear deterrent like SLBMs. Cruise missiles are an option but much more vulnerable to defences.
However the defence budget needs to be increased not cut. If you want to make savings then reduce the social security budget. The first responsibility of the UK government is the defence of the UK.