The Cold War RAF was pretty capable of defending these islands, though even then those of us in the job thought the numbers were fairly marginal. In my time, the aircraft concerned varied from the Lightning (ineffective but spectacular) through the F4K/M, the F4J (terrific aircraft) and the Tornado F3 (better on paper than in the air). In 1990 there were around 8 squadrons (15 ac per squadron) of dedicated air-defence aircraft, backed up with several RAF Regt. anti-air missile squadrons. Now there are four dual-role air-defence/ground attack squadrons of Typhoons, of which at any one time just 4 aircraft are dedicated to defending UK territorial airspace at short notice. All the missile back-up is gone, and the ground attack role often means that many of these aircraft aren't even in the UK. The Typhoon's a great aircraft, but it's not a great deal more effective than the F4J was in terms of how many intruders it can kill, and how fast or how far it can go to do it. And the four available will quickly be overwhelmed if the Russians decide to send more than 2 Tu95s to see how good we are at seeing them off.
All that said, this woman saw a long, thin silver aircraft near St Mawgan (Newquay Airport) while she was undergoing a driving lesson. The only aircraft that land at St Mawgan these days are civilian, and mostly the Dash 8 Q400 - which is a particularly long, thin prop-driven aircraft which, like most airliners, is mostly silver underneath. Just sayin'.
