[yohui]

True, the continent of Europe (10.2 million km^2) is larger than the United States (9.8 million km^2), but the context suggests wskinner meant a comparable geopolitical entity such as the EU.

The US covers roughly twice as much area as the EU (4.5 million km^2), which includes most of the countries we're talking about. If we want to add the rest of continental Europe (mainly western Russia), we might also add the rest of continental North America (mainly Canada).