That's a tricky one. From my bubble, the first thing I would to is to stop digging the hole any deeper - stopping any ongoing Azure (and other US cloud migrations), not buying into new products such as MS Fabric etc.

But what really would rock the boat would be a MS 365 competitor, since that's currently suffocating everything, because everything is included: email, files, office suite, chat... None of these have to be the Same Product (and I'd prefer specialization), but the integration between different apps should be painless. So, protocols.

If nation states could onshore that package, it would even out the playing field for the other, more optional applications

I think what makes Microsoft so hard to challenge is not one product but the fact they have a tightly integrated ecosystem. Everything is coupled with the Active Directory, Azure and Office365. By themselves these components aren't irreplaceable but no company has ever been able to offer as wide a range of products.