its what they are forced into by the actions of an EU with a foreign policy and military capability with its own agenda.
Unlike the Americans in say Iraq or Afghanistan, eh? Far more recent (non-European) examples, which cost far more Commonwealth blood and treasure than Kosovo, Bosnia etc, which presumably you were happy to go along with.
Also, where was mighty Blighty in these 'recent' European conflicts? Front and centre, urging our European colleagues into action, or quietly waiting for the Americans to arrive?
Hypothetically, imagine an EU army sparking a conflict between Greece and Turkey which drags in Russia, and then invoking Article 5.
Greece and Turkey are more than capable of getting into a fight on their own, with or without the hypothetical involvement of an EU army (this scenario is right up there with 'Turkey is about to join the EU and unleash 70 million Turks onto our shores' of 2016 fame. Remember that chestnut?)
I'd argue that where we have had a platform with poor capability, performance or reliability, its been a eurofudge project.
There's also been some successes - Typhoon, MRTT (heaven forfend we'd all opted for the KC-46...). Its not like we've been immune to procurement f*ck-ups/bodges/delays, the QE carriers and Nimrod AEW being two recent (and hugely expensive) examples.
You're actually arguing for the US rather than anything to do with the UK or Commonwealth.