I don't think, short of nuclear war, we are ever going to have a true SHTF moment. Or even a "flushed down the toilet one". I believe we are in a long-term erosion, a slow collapse of everything that made this country great. Very similar to how the Roman Empire ended. Most people never notice it, or if they do they don't care due to what's called these days "normalcy bias" (what used to be referred to as being like an ostrich with your head in the sand [or up your nether regions, if you prefer]). Some actively encourage it, thinking they can "Build Back Better" than it ever was before.
Others, who despise what is happening, also subscribe to the "tear it down and start over model", not realizing that their solution, while possibly good for themselves, is just as damning to society as a whole.
The United States is without a doubt the most noble experiment in human history, the idea that a people can truly govern themselves- but it's been sabotaged since its inception by greed and special interests. Somehow, though, we have never stopped being Americans and holding on to that ideal.
I rarely see that now, however. When I meet people now and talk to them they don't identify as Americans, but as sub-groups.I believe society has truly ceased to think of itself as American, having been maneuvered by the education, media and government into primarily identify as sub groups- defined by any available division. Republicans, Democrats, vaxxed, unvaxxed, straight, gay, pro-abortion, anti-abortion, pro-gun, anti-gun, so on and so forth ad nauseum; all designed to pit us against each other so we don't notice, or if we do, don't have the wherewithal to deal with, the slow grind of our societal collapse. Society spends so much time and energy dealing with those issues, egged on by those maneuvering groups, that the greater issue is pushed aside.
Those of us who do notice and try to speak out are branded fringe elements (just look at current DHS policy), essentially becoming Cassandras crying out in vain.
So, PK, I believe "it" already started a long time ago, and "it" ain't gonna be over for a long time to come.
I think all we can do is prepare, cling to our morals and beliefs, and fight against "it" as best we can. I hold out hope that we have our own version of a Cincinnatus somewhere in our future to remind the rest of the country what freedom and individualism really mean.