According to the sources cited within this paragraph, there is a scientific consensus that "currently available food derived from GM crops poses no greater risk to human health than conventional food, but that each GM food needs to be tested on a case-by-case basis before introduction."
However, United States and European Union seem to have very different policies regarding GM food:
USA - according to this source,
The United States does not have any federal legislation that is specific to genetically modified organisms (GMOs). Rather, GMOs are regulated pursuant to health, safety, and environmental legislation governing conventional products.
GMOs are not restricted categorically from the US food supply. As discussed above, the FDA treats foods derived from GMOs like those derived from conventionally bred plants, and therefore most foods derived from GM plants are classified as presumptively “generally recognized as safe.
European Union - according to this paragraph (Approach)
uses the precautionary principle demanding a pre-market authorisation for any GMO to enter the market and a post-market environmental monitoring.
Question: Why is policy regarding GM food so different between USA and EU?