True, there were a few lucrative markets for our products in Europe, and imports were nice, too. But in early America, the prevailing attitude toward what happened on the other side of the Atlantic was the one expressed by that old Polish saying that for some reason is currently becoming popular here: "Not our monkeys, not our circus."
The attitude started to become slightly more problematic with the advent of ships powered by something other than the wind. Trans-Atlantic travel became a matter of days rather than months, and modern ships became a great deal safer. And then came the airplane, and it became a matter of hours.
With the exception of Pearl Harbor, we weren't bombed in World War II, although the theoretical possibility existed. There was, of course, the failed Japanese attacks on our West coast with incendiary and plague balloons. But with the advent of jet engines and the intercontinental ballistic missile (and, of course, nuclear weapons), suddenly Fortress America stopped being a sane model of the world.
That didn't stop the isolationists who kept us aloof from World War II until the threat from Germany and Japan because critical and thus prevented us from dealing with it decisively and far less expensively at some earlier point from continuing to spew their nonsense. As much respect as I have in most respects for Robert A. Taft, his foreign policy would have made him a threat to our national security as president (at least initially; I have no doubt that he would quickly have "evolved," as the expression goes. He was too smart to have stuck with an approach to the world as president that wasn't working for him).
I have less respect for Ron Paul, a fringe figure best written off as a sincere but goofy extremist. And then, there's the newest presidential candidate to embrace isolationism, Donald J. Trump. And he seems to be speaking to an inward-turning urge currently very prevalent in the USA.
It's an urge I can understand. When France stabbed us in the back in the United Nations Security Council, breaking its promise to support the Second Gulf War (remember "Freedom Fries?") I was as angry as anybody. Whenever some European politician or journalist or YouTube commenter makes some snarky crack about the United States, I, too, experience the urge to retreat into Fortress America and let the ungrateful wretches stew in their own juice. At then there's Vietnam, and the Gulf and Afghanistan wars and the specter of "mission creep." Despite the attempts of the media to obscure this point, of course, the latter wars never even approached the price in casualties we paid in Vietnam. But the wars have seemed to go on and on, with no prospect of ending and only the prospect of more of the same in the future.
But my reason and my sense of proportion soon kick in. I realize, as Paul and Trump and Pat Buchanan and their ilk do not, the chaos that would descend on the world were America to abandon our position as the "biggest kid on the block" of the international community. A strong argument can be made for a more multilateralist approach to threats to collective security in most cases, with the caveat that sometimes the international community is the one with its head in the sand and unilateral action may be necessary. But perhaps not as often as we've conducted it in the past. And even those multilateral actions require our leadership. It's expected of us, and it would be irresponsible not to provide it.
And then, there's the cost that the urge to withdraw from the world and the reluctance to pay the price our role in it demands of us has already exacted: the perception not only by our allies but by the world that the United States does not honor its commitments, and that when the going gets tough, we go home. We have convinced the world that we are neither allies to be trusted nor enemies to fear. However big the stick we have carried, we put it down when our arms grow tired of swinging it, with the consequence that neither we nor anyone else is much better off than if we'd never picked it up in the first place.
Trump's protectionist approach to trade would wreck our economy. I have no doubt that Hillary Clinton will be able to make that point quite clearly in the months ahead. But it's an open question whether the American people- war-weary and tired of the both the burden of world leadership and the gratuitous rotten eggs that get thrown at nations that carry it- are ready to continue to bear that burden, as Hillary will urge, or will finally decide to follow Trump in what Monty Python fans might think of as the Sir Robin approach to the problems of the world: "Run away yy!"