You don't have to worry about this. Ideas are what matter - American startups aren't spun from any special cloth or unique talent. That's jingoist hoo-haa.

Having worked for a few US-based startups, I can't help but roll my eyes when people venerate our business culture. At the bottom, startups are built with the cheapest foreign labor and shipped with the shittiest minimum viable product. Widespread success is attained less through iteration on innovation, and more through exploiting moral ambiguity and offshoring better than your competitors. You're not in a race to disrupt Apple and Google, you're in a race to find something equally as lucrative as an advertising or service monopoly. To beat America at it's own game, you'd have to import our own ignorant politics. Even China can't fully embrace that level of contradictory stupidity.

I guess that's not really a new opinion, and I'm sure HN will drag me for bringing it up. My $0.02 is that you don't want an American economy, and Europe will work very hard to ensure startups don't reprise the mistakes of America's most lucrative (and harmful) success stories.