Why are Americans more risk averse about medicine than Europeans?

The stereotype is that Americans are more risk-loving and entrepreneurial than the less-rugged Europeans who instead seek shelter under the umbrella of the welfare state.  Yet when I talk about the FDA I point out that for many decades (from say the late 1960s to PDUFA in 1993 and perhaps again more recently) the FDA lagged behind its European counterparts in approving new drugs.  U.S. risk aversion in drug approvals is especially peculiar since the major scare which increased FDA powers and slowed down approvals was the thalidomide disaster but thalidomide was approved in Europe not in the U.S.  Nevertheless, we were the ones who got scared.

More recently, Scott Gotlieb argues that the Europeans have pushed H1N1 vaccine production forward using adjuvants and novel production techniques while the US has chosen less risky (some might say less entrepreneurial) older approaches.

The tort system is sometimes blamed for excess U.S. risk aversion but in both these cases it's mostly the U.S. government which is more risk averse than its European counterpart.  Moreover, the US government is more risk averse over medical matters and not say about sending troops abroad or about providing a safety net for other risks.

I think this is a puzzle.  Why has the U.S. government been more risk averse with regard to medicine than European governments but less risk averse in other areas?