The famous British Historian Arnold J. Toynbee (1889-1975) said that 19 to 21 major civilizations that had come and gone since man began to form governments. He said, the American civilization is one of five that remain. He point out that almost all had not been overthrown by some outside aggressors, but by moral and spiritual collapse from the inside.
That brings me to General Douglas MacArthur. As a quick aside, in 1907, while on an engineering assignment in Milwaukee, MacArthur used to live in a Hotel where the Grand Avenue Mall stands today. MacArthur insisted, "History fails to record a single precedent in which nations subject to moral decay have not passed into political and economic decline. There has been either a spiritual awakening to overcome the moral lapse, or a progressive deterioration leading to ultimate national disaster."
I recently came across this quote when reading a sermon by F. B. Meyer. He wrote about sensuality and sexual immorality and how it destroys a nation. He wrote, "There is no sin which will sooner bring about a nations fall. If history teaches anything, it teaches that sensual indulgence is the surest way to national ruin. Society, in not condemning this sin condemns itself."