What was the time period In your words that America lost It's greatness?
Like any sin, it took place over a period of time with an opportunity to repent.
1. Assassination of JFK, Martin Luther King Jr., RFK, and Medgar Evers. These are events that must be properly investigated. It has become quite clear that they weren't, they were covered up, and we had a deep state growing like a cancer in our midst.
2. During Ronald Reagan's presidency it became clear that this cancer was growing and spreading with the Iran Contra affair.
3. 911 was an inside job revealing that the Satanists were in full control. The American people were mesmerized by their TV and high tech toys and were willing to just blame that event on "innocent" people (by that I mean innocent of that crime). However, there was still an opportunity to repent, but instead the US proclaimed they would "build back better" indicating a proud rebellion against God.
4. 2008 mortgage meltdown was a further indication of how utterly corrupt the whole system was from the bankers all the way to the politicians. Stealing homes from widows and the poor and claiming the criminals were too big to fail. If 911 was a plain and obvious warning from God that He would judge America, 2008 was his anger going white hot.
5. 2020 Pandemic -- 19 years after 911 and a very plain declaration that the judgement had begun. Still you see the brazen corruption, stealing an election, printing money like they won the lottery.
6. 2022 -- War in Ukraine, revelations concerning election fraud, revelations concerning the vaccine, revelations concerning Epstein, revelations concerning the Biden crime family -- this was the "writing on the wall" by the mysterious hand saying the US has been weighed in the balance and been found wanting.
7. There have been multiple warnings by prophets going all the way back to the 1980s. However the die is cast, the total destruction of the US in a single hour has already been set in motion at the command of God.