One reason it might be hard for people of our era to embrace realism is you have to tell people hard truths they don't like hearing. And we aren't a country right now that likes to hear unpleasant things (our kids aren't all above average, debts & deficits matter, no free ). 1/

2/ And who likes to tell people these things, especially when you become more and more familiar with the others whose approbation you may desire and disapprobation you wish to avoid (which is entirely human as Smith points out in The Theory of Moral Sentiments)? 3/

3/ Of course, technology (air travel, Zoom, etc) makes these interactions easier, like with the global elite involved in discussions of foreign policy. So realists have to carefully tread and diplomatically tell truths that are hard to hear for many audiences.