You can learn about foreign affairs and become educated without visiting other counties, it's not a requirement. You'll learn more in books than you'll learn drinking a margarita in Cancun resort.
Visiting other countries doesn't, by definition, lead to learning about foreign affairs and becoming educated of other cultures. I studied abroad and some of my fellow study abroad students didn't develop any understanding of foreign affairs or enlightenment about culture.
No place that has been bombed lately are where tourists will travel to.
It leads to an uneducated populace, ignorant of other cultures and with a very limited perspective of world affairs.
People's understanding of the world becomes limited to what you hear from the state department and the news media.
Makes it easy to drop bombs on people a world away if you never bothered to get to know the people or places you're destroying.