It took 100 million to get to falcon 1, and the company was probably not viable until NASA gave space X the crs1 contract for >1billion...

And where did that initial money come from? Musks sale of PayPal shares, which he got when PayPal acquired his payments company... Would that have happened if he'd started his payments company in Europe? Would Compaq or an equivalent have been interested in paying for zip2, which provided the initial money to found x.com if he'd built zip2 in Europe?

Musk deliberately and intentionally moved to silicon valley, and I think a big part of the reason was almost certainly that the US is more prepared to invest money in these kinds of ventures.