Unfortunately, with thousands of air flights a day into the US, we can't keep foreign influences out for long. The oceans aren't wide or deep enough to keep them out. We're being invaded, not just by Mexicans, but every other nation to the south, and everyone else who can get here by hook or by crook. Isolationism is a wonderful dream, but globalization (big business' greed), killed it, and I'm still in mourning.
I do not propose, and do not favor, isolationism. I'm not a Buchananite. Nor is isolationism what Washington advocated in his Farewell. Instead I advocate Washingtonian non-interventionism.
"Against the insidious wiles of foreign influence (I conjure you to believe me, fellow-citizens) the jealousy of a free people ought to be constantly awake, since history and experience prove that foreign influence is one of the most baneful foes of republican government. But that jealousy to be useful must be impartial; else it becomes the instrument of the very influence to be avoided, instead of a defense against it. Excessive partiality for one foreign nation and excessive dislike of another cause those whom they actuate to see danger only on one side, and serve to veil and even second the arts of influence on the other. Real patriots who may resist the intrigues of the favorite are liable to become suspected and odious, while its tools and dupes usurp the applause and confidence of the people, to surrender their interests.
The great rule of conduct for us in regard to foreign nations is in extending our commercial relations, to have with them as little political connection as possible."
The loudest proponents on Free Republic of American interventionism in the Middle East in my experience have the least inkling of the Balfour declaration, its purpose, and its repercussions.