Is there such a thing as a "Black Project" outside of the US?

I wonder.

so much discussion these days is about joint production or sharing technology (Typhoon, Rafale, F35, Gripen to name but a few).

So i’m wondering if there is such a thing as a developmental aircraft which European governments don’t wnat to share with anyone?

Taranis isn’t being talked about in the same way that Neuron is (in terms of everyone pooling resources including Brasil).

Being of the old HALO conspiracy school, I would like to think the US aren’t the only ones with a thing or two up their sleeves…