In terms of headline figures, the UK certainly "appears" to get less bang for it's buck compared with some other countries. I suspect there is a combination of several factors in play, although I'd struggle to say exactly what proportion of where we are is attributable to each, eg:
- Expensive kit eg nuclear submarines
- Being charged top dollar by a near-monopoly "UK" supplier
- Investing in building and supporting a genuine capability as opposed to trophy assets that arent supported by the less glamorous investment needed to produce genuine capability
- Inefficiency / poor financial control
- The costs of maintaing the strategic UK manufacturing base instead of outsourcing