We are "dependent on others for key force elements". Most wars do have "bleak" outcomes, whimpering not climaxing - ask 2million Mothers of 1986 Iran/Iraq, or any of Africa's tribal conflicts.
UK has not fought solo in modern times - Corporate had much US kit+Intel. US has done so twice, ever - v.GB, 1812, Spain, 1896. Vietnam had Oz, RoK, Phils. and the invaded Ally. Since 1991 we have been trying to hold Defence spend at the level of our business competitors - 2% of our wealth, not Cold War 7%, because history tells us that Nazis and Sovs. lost by spending to death. So Ministers ration, juggle and role-share with mates. In Helmand those are Canucks, Dutch and the invaded Ally; in Iraq more. An EU team would bring in Ireland, Sweden - even Switzerland can show interest; Austria, Finland can participate, but, by Treaty, can't join NATO (until/unless Russia does). It's not a contest, UK+US, v.UK+EU, or EU-UK: we're all repelling Threats, ever-changing and outpacing the procurement cycle.
Ministers would welcome chopping big-ticket procurement, to kit our Forces only for lo-intensity: Vote Green, that's what you might get. They would be glad not to attend BN corteges: Vote Respect, that's what you will get. G8 are dealing with N.Korea by talking, and trying to deal with Iran likewise. Wish them well. It worked with Libya. But share the big stick.