> Microsoft Windows is both so widely used and so infrastructure-critical (you can't replace it with a different OS and keep running your native Windows applications)
If the US declared war on part or all of Europe, and caused Microsoft to send updates bricking legitimate Windows installs within that region, the victims could still use pirated Windows to run their native Windows applications. I doubt there would be any legal repercussions.
It would take a huge amount of time, effort and money to reinstall and reconfigure, say, 80% of all computers in a country that happen to be running Windows 7 or newer. To recover all the data from backups (assuming the backup servers weren't running Windows as well). To replace any literally bricked hardware.
Meanwhile, many very critical systems that happen to be implemented on Windows would shut down for weeks or months. Look at the current ransomware attack on the NHS. Now imagine taking down all health services, ISP services, maybe electricity or gas or water companies, supermarkets, distribution and shipping management, police and government records...
Yes, these things usually have non-Windows components on big iron or Linux servers. But if you take out all the Windows clients, and however many Windows servers do exist, then the system as a whole cannot function.
This could be a part of a (cyber)war effort. Instead of, or before, sending in the army to attack, you cripple the enemy's economy and civil infrastructure. You even have a chance of maintaining plausible deniability if you attack the MS update distribution channel, or serve them a sufficiently secret order that doesn't get leaked.
Then again, if US declared war on Europe, they'd just brick the hardware (which is what bricking usually means), or take out key parts of the backbone, then it doesn't really matter what the capabilities of individual users are.
When the problem is "we need to be able to run our existing native Windows applications", this matters. No matter what Microsoft does, a country can't be prevented from running their own native Windows applications on their own machines. They have all the necessary software and expertise locally. One strike is not a victory.
Because today it's easier to destroy a country completely without boots on the ground, so people won't have to occupy it and won't bother to rebuild it?
IMHO, major wars will only happen somewhere in Asia...between China, Russia, India and Pakistan (all nuclear powers). They all have border issues are relatively large countries and China and India have potential to be local superpowers. China will need Lebensraum and move into Siberia and that might start it all. USA will probably seek to sell arms to both sides and stay out of it:).
If the US declared war on part or all of Europe, and caused Microsoft to send updates bricking legitimate Windows installs within that region, the victims could still use pirated Windows to run their native Windows applications. I doubt there would be any legal repercussions.