1. When Jefferson wrote, it took a lot of time to get across the atlantic ocean. There was no weaponry capable of reaching our shores from Europe. Do you think that modern times might cause Jefferson to have a different outlook, considering the vastly different circumstances. He thought of us as miraculously separated and protected from Europe's woes. Hasn't that changed?
2. Had we followed Jefferson's thinking, that would have meant staying out of WW2 and the Cold War. Would those have been correct stances to take?
Had we followed Jefferson's thinking we would have stayed out of WW1, and the Treaty of Versailles wouldn't have engendered the conditions for WW2 and the Cold War. That would be the correct stance.
What a preposterous statement! We were attacked in World War II. We were the principal target in the Cold War. You need to study Jefferson, more carefully. Jefferson advised General Washington, when he was Washington's Secretary of State, that in foreign policy, you need to punish the first insult, lest it lead to many others.
But neither Jefferson nor Washington would ever have condoned our meddling in the affairs of nations in the Caucuses! This is pure insanity, and will create problems for many years to come.