Evidence of this was Trump actually being laughed at when delivering a speech to the UN. By Diplomats. Who were on the clock.
Yeah, well, there's only so long you can ride the post-war boom. The US didn't get directly touched by the World Wars in the sense that the infrastructure wasn't obliterated. We had endless resources and cheap labor, and a market in the countries that needed our resources and products during the war and that were severely damaged by the war and needed our products thereafter. There's only so long you can exploit all of those, before the saturation point hits or the market dries up. And then, what's left? A damaged environment, rust belt cities, unsustainable expectations from the citizenry.
I am glad I didn't go into government service. That is what I trained for, in grad school. I was really gung-ho about going into federal service. At about the time I was finishing up, the feds were in one of the popularly-mandated downsizing phases, so I went into a different sphere of work. Looking back over the last 20 years, I think that was probably a good thing, as federal workers are underpaid (as a whole), undervalued, and, now, are having to use soup kitchens to get by. As always, the fatcats aren't hurting. It's never the fatcats who do, is it.