Interesting, thanks for the clarity - it is the answer I expected.
If I could paraphrase the answer somewhat harshly "only we are competent to undertake T&E and all others cannot be trusted, nor relied upon".
So, if that is somewhat close to the situation, why are none of the vast range of US military aircraft failing regularly?
Or could it be that most of our T&E capability is marking others homework, after it has been corrected by another teacher and while we do find things that we do not like, it rarely if ever, is of any substance.
So, back to an example. Once the F35 is in service with the US, why on earth should we be testing it ? It flies, it works, it doesn't drop out of the sky, so why do we decide whether it is fit to fly?
Sounds like another excuse to spend money to me!