That's not actually true. The US is 3,794,101 sq mi. Europe is 3,930,520 sq miles
However, Europe is almost entirely concentrated in walkable, urban areas -- even beyond the major cities, small towns are accessible by train, navigable by foot, and have excellent support in the form of public transportation. If people do have "cars," they tend to be tiny or Vespas.
There's no reason we can't have the same system here, except that we absolutely suck at infrastructure investment. It's really not that hard to build an urban environment, and it's overwhelmingly popular with people who can afford it. The exurbs of Las Vegas and Miami are completely worthless, and will be even more so in a future with higher fuel costs, water scarcity, and resettlement in urban environments.
However, Europe is almost entirely concentrated in walkable, urban areas -- even beyond the major cities, small towns are accessible by train, navigable by foot, and have excellent support in the form of public transportation. If people do have "cars," they tend to be tiny or Vespas.
There's no reason we can't have the same system here, except that we absolutely suck at infrastructure investment. It's really not that hard to build an urban environment, and it's overwhelmingly popular with people who can afford it. The exurbs of Las Vegas and Miami are completely worthless, and will be even more so in a future with higher fuel costs, water scarcity, and resettlement in urban environments.