I would suggest that as a believer and one who has served in many capacities in different churches and congregations for more than 50 years that your assertion that God has “lifted a hedge of protection around America” is a faulty interpretation of reality.
Neither you nor I know the mind of God, nor are we intended to, as a reading of Scripture will tell you.
America has been the product of a vast territory of some 3 million square miles, not counting Alaska, that was lightly populated when Europeans first settled, had bountiful resources and suitable climate to support an agricultural and, later, industrial base for the manufacturing economy that came later. We were isolated from other nations and had little need for a large standing army.
A steady supply of cheap labor from Europe enabled the nation to extend from the Atlantic to the Pacific, and while many had their Bibles in hand, we also enslaved others to tend our plantations and simply killed and cheated the native American population as the nation expanded from the original 13 colonies. How could America not succeed with the advantages present?
If you wish to persist in the idea that somehow God favored America, but looked with disfavor on other nations, say France or Italy, then that’s your call. I am old enough to have served in combat during World War II. In my boyhood, I heard the same tales of impending collapse of America, intensified with the rise of Hitler’s Germany and Stalin’s Soviet Union. I heard many preachers in those days refer to prophecies from the Old Testament and New Testament that “pointed” to the end times, and predictions in the late 1930s that Mussolini, Italy’s dictator, would later emerge as the anti-Christ.
As far as a day of prayer and repentance, I suggest every day is suitable for prayer and repentance, emphasized on Sunday morning with the prayer of confession. I am well aware of authors, many earnest and believing what they say, a few simply playing on the fears of those who have little theological background or understanding, writing for their own gain based on their interpretations of various biblical passages – whether or not they really believed what they were saying.
I understand exactly what you are saying, and if you wish to identify yourself as a “nutty … zealot,” then that’s your call. I don’t believe you are; but I believe that you and a few others believe that some magical prophetical insights are contained in the Bible to explain today’s world. Obviously, Holy Scripture contains Commandments and the teachings of Jesus that are clear as to how life should be lived. But understanding the Bible also requires knowledge of the context of the remarks, the times in which the words were written – and then words translated into Greek and retranslated into other languages – and the history and other events taking place when the particular verses and passages were written.
I need prayer, and so do you.