Re: Just change the current tax laws.
"Possibly the right answer is percentage profit tax, i.e. if 10% of a company's revenue is in France then they would page French tax on 10% of their global profit regardless of inter-company accounting. This may be difficult though assuming different countries have different rules on what counts as taxable profit."
So 10 countries = 100% of their global profit?
Great way to kill other global firms when google can pause transaction for a year to get 100% monopoly when all the other global firms bankrupted from the extreme tax.
Think about this for once, if you are working in one job and you provided free services one time for a trip in another country. BAM +10% of your global profit for tax. And no, any 'exceptions' you make from here is additional loopholes google and the likes can abuse when other global firms suffer.