It's even more absurd to suggest that this can be done in response to the US becoming more hostile than they are today. By the time they are more hostile, we're talking about open hostilities. It's only safe to assume that they will have exfiltrated all the data they are interested in, and then sabotaged or destroy as much of the hardware as possible (as can be done remotely), making the data center next to worthless. And prior to nationalization it was "their data-center", they were entirely within their "rights" to sabotage and destroy it.
The time to migrate away from data-centers to minimize geo political risk is now, not when the current data centers operators are actively trying to deal damage.
But long before that, I believe there will be other noticeable effects. As someone working in a medium sized European company, with substantial investments across private infrastructures, AWS, GCP and some Azure, I can testify to that since last couple of weeks the Public Cloud Exit strategies around having services being prepared is a very hot topic. This concerns both existing services preparations as well as enforcing standards and configurations for new services.
To obey local laws
The USA is going "unlawful", so the risks are technical and real. Local laws do not apply
I have not looked at the US-EU agreement.
You don't need an agreement.
Tthe EU commission has tried to create schemes bypassing the issue, and twice they were dismantled by the EU supreme court.
the enemy will never put you into a position where the rational thing to do is to launch your nukes (nationalise their data centres)
but they will push and push up against that line
the way to deal with this is gradual decoupling, ideally backed up by legislation and government subsidy
The reserve status is overblown. The question is if not the USD what asset would reserves go into. Certainly not the yuan with china's currency controls.
I see the point. But I would not underestimate the grit of Europeans when backed into a corner, like this
The USA a Europe had very friendly relations for decades, that has changed overnight.
All bets are off