I am going to cherry pick your post here Tundra, forgive me. Gibbon, in my opinion, is not a credible source any longer for the decline in particular, anyway. I find his first five volumes to be very comprehensive and an accurate study of the sociopolitical status of Rome throughout its history. However, his ending thesis regarding Vandal invasion is wrong, in my opinion. He attributed it to a loss of morality, which stemmed from their straying from Catholic faith. This was clear and uncut propaganda from Gibbon, an unfortunate inclusion in such a masterful piece of scholarship. His faith obstructed his objective, academic conclusion. Please do remember, that this work was finished and published during the most tumultuous time in human thought: the Enlightenment. Gibbon's work served as a counter to many philosophes' works such as Voltaire's Spirit of Nations and Treatise on Tolerance. There was as much allegorical work as there was historical, which is why we must be cautious when using Gibbon's work in academic settings regarding the fall of Rome as an idea. While I believe that Gibbon's monstrosity of a work is a very important piece of understanding Rome and its historiography, I cannot possibly use his final thesis as fact. We can use it, of course, as a great foundation and as a particular lens or viewpoint. But, I would be apprehensive about siding with him or even using his morality question as a basis of reason when determining the cause of the fall itself.
I don't disagree, I just threw him in my little list, as his viewpoint on one singular subject fit my point I was making, regarding comparing the fall of Rome to Trump and current issues/events.
I would contend that the opposite is true in terms of Gibbon's theme regarding early Christianity, and the Roman state's failure due to straying from early Catholic beliefs. IMO there is a far stronger argument to be made that straying from earlier (back as far as the mid Republic period) Roman values, ideas, and religion, was responsible - at least partially - for the collapse.
So I don't disagree. What I do disagree with is those who cherry pick incidents regarding Trump, and make comparisons to the worst leaders Rome had, as though they've said something noteworthy. I could do the same, with pages of examples of Obama, Bush, Clinton, Reagan, all the way back to Washington.
edit - +1 for SPQR by Beard, it is one of my favorites as well, I give copies as gifts all the time to friends and relatives who enjoy history. For more specific Roman military history, Goldsworthy, Hughes, Kulikowski, and Ruebel all have written numerous excellent books on the subject. If anyone wants to borrow any of the epubs/etc from me, or even see my list of books on the subject I can loan out, PM me.