The notion about IRBM first stages – or only stages – would make a lot more sense if Europe showed even the slightest inclination toward building any weaponry capable of actually deterring Russia – but it doesn’t. The French used to have some siloed IRBMs back in Soviet Union times but pulled them all out of the ground and retired them some time ago.

The Vega 1st stages do have a side hustle, as it were. These motors are also used as strap-on SRBs – either two or four at a time – on both models of Ariane 6.

“Neutral hexanitrogen allotrope” sounds very exotic. But if it’s actually a thing potentially useful to drive rockets – especially military missiles – I would expect one of those Tolkein-named defense start-ups in El Segundo, CA to be the ones to make that happen – not Europeans. You’d probably have to scour all of Europe to scrape up even a single liter of the sort of entrepreneurial “irrational exuberance” we manufacture by the metric tonne here in the US.

The neutral hexanitrogen allotrope intrigues me.
I think it is stored immersed in liquid nitrogen, which makes me wonder if it could serve as a monopropellant rocket.

That might require rugged solid rocket handling tech. The Sprint ABM used mixed explosives for propellant.

An all nitrogen rocket? No combustion? Sounds great–now to just get it to work.

Thing is, even if the requested mandate is enacted, it isn’t likely to save either Arianespace or Avio in the long term. Arianespace, in particular, has a rocket – Ariane 6 – that is designed to address a market that was still large when design work started, but which has diminished greatly since – namely, the launching of large geosynchronous orbit comsats.

Ariane 6 will see modest service deploying a fraction of the initial Kuiper constellation, but is unlikely to get any more Kuiper work beyond that already contracted as the partially reusable New Glenn, Neutron and Eclipse rockets in the US will all have better economics.

Avio’s rockets – the Vega and Vega-C – have not proven to be reliable. Perhaps that will change and perhaps the upcoming Vega-E will avoid the same teething troubles. But the Vegas are still entirely expendable – which makes them quite pricey – and use solid motors for all but their uppermost kick stages – which provides a rougher ride uphill than do liquid-propellant rockets.

The various European small rocket start-ups will, under any Europe-launches-on-European-launchers-only mandate, have room – perhaps quite a bit of it – to undercut the legacy players for launches of small and medium satellites, especially to LEO where most new payloads seem to be headed. If one or two of them succeed well enough to follow in the footsteps of Rocket Lab and Firefly and gin up new partially-reusable medium launchers, they will be able to put both Arianespace and Avio entirely out of business not too far down the road.

As for “practice,” the reason the European launch companies don’t get as many launch opportunities as US and PRC providers is that Europe doesn’t generate many. The biggest difference is in LEO broadband and direct-to-device satellite constellation launches. The only two such already in service are Starlink and OneWeb which both had their origins in the US private sector. So do the nascent third and fourth such, Kuiper and AST Spacemobile.

Europe, in contrast, is, as is its usual wont, trying to gin up an all-governmental LEO broadband constellation effort dubbed IRIS2. The project will probably never materialize as it would have hopeless economics if launched on Ariane 6s. Even the Europeans are beginning to see the future limits of business-as-usual European-style.

The only substantive European space endeavors a decade hence are going to be those that emerge from the European private sector and which, additionally, are built by their founders to be competitive in a global market, not just a mingy European one with a fence around it.