Today it is not possible. Since you can't talk about trade, you can talk about culture. The United States are a major export of culture throughout the world, which includes things like movies, music, books, and similar. These works of art often depict traits of the American culture and they are appealing to numerous people worldwide. Even if the US wanted to end all connections to Europeans and other countries worldwide, the culture would still carry on and keep spreading because people worldwide want it to spread.
The main element of the Constitution that gives people this right is the right to freedom of speech, will allows people to protest rules that consider to be unjust.
Germany was punished in the Treaty of Versailles and then suffered at the hands of the worldwide economic depression. This made the conditions just right for Hitler to rise to power.
In 1917, Congress passed the Federal Espionage Act. This law prohibited all false statements intending to interfere with the military forces of the country or to promote the success of its enemies.
