Re: Making life easier - for an adversary
A little history: in the Falklands War the Argentine airforce flew French planes armed with French missiles. However, they had neither nor the licence nor the know-how to repair stuff or make new ones and the French government refused to supply them. So, yes, battlefield capability depends upon logistics.
In practice, some kind of resource pooling for modern weapons is essential because of their complexity and price. This one of the reasons behind the proposed "European Defence Force" and even the aircraft carriers being shared by the UK and France and some NATO initiatives. Turkey makes sense for some stuff if the job is bombing somewhere in the Middle East. But, as the recent spat between Germany and Turkey over the AWACS stationed there has shown, you can very quickly lose access: Germany has since moved the AWACS planes to Jordan because the Turkish repeatedly denied MPs access to the base. Obviously, something like this would never happen to the UK…
But more fundamentally, does the UK really need the F35s that it can neither afford nor maintain?