Re: What will happen during a war?
I see the armchair generals and strategists are out in force.
What use is F35 you ask? Who knows. It's impossible to know. We ordered some of the things about 5 years ago, having been putting money into the project for another 5-10 years before that, and we're not getting all the planes we ordered for another 5-10 years. Once we've got them, we may well buy more, when the price has come down a bit. Or not.
But the important point is that we'll be operating the things until 2040-2060. What will be the global security environment in 20-40 years time? Anyone? Anyone?
However at the moment we're using the RAF to fight ISIS, plus we've recently used it in Libya. And there's now a considerable body of thought that says we should have used it against Syria's chemical weapons capability in 2013 (where stealth might actually have been useful), though opinions differ obviously.
But the other big job the RAF are currently doing is patrolling the skies over the Baltic States. Because we're treaty-bound to defend them via NATO. But it's considered better to have forces in place to deter Russia, than to try to retake the places after they've fallen.
I don't think anyone is currently suggesting there's any threat to the UK itself. Other than from France of course. We've got to be prepared to fight off the Frogs...
But the point is Russia currently have form in invading their neighbours in order to "protect" Russian minorities left over from Soviet days. And that population is a running sore in Baltic States politicsj - particularly the older generation who only speak Russian and have a bit of nostalgia for the "good old days". So if we're going to have those countries in NATO we need a credible force in place,so Russia can't just conquer them in a day. Because if they have to mobilise sufficient force to do it, we've got time to react and reinforce ourselves.
But also the Russians know they've got to kill lots of British, US, German servicement to do it. Which then means other NATO governments have no excuse to just shrug their shoulders, up sanctions a bit and do the old Yes Minister "there's nothing we can do" bit.
The nuclear threat isn't credible if you're going from a standing start to WWIII. And realistically we're not going to re-invade somewhere on Russia's border once lost. The so the answer is credible military force in place (while not being big enough to actually threaten Russia), with reinforcement possible, backed by the nuclear deterrent.
Of course we could just have stuck with our old planes, but Tornado is getting old. And also, while you can fly old planes, and then buy new off-the-shelf ones to meet a threat quite quickly. Maybe 2 or 3 years to retrain pilots and start getting the new ones (even quicker if you buy second-hand like Canada buying old Aussie F18s). You can't do that with a carrier capability. Which as a trading nation on an island that imports food, oil and goods - is something quite useful. As well as for power projection.
To get a carrier designed and built and takes years. You've then got to train a crew to run it safely. Then train the pilots and buy the planes. Even in a rush and buying off-the-shelf designs you'd struggle to get an operational carrier within a decade. That's why the Russians had so much trouble with sending theirs to Syria - because even not regularly using it means you can't operate it properly. Carrier ops are hard. Complex, dangerous and expensive.