So, in my innumerable Command editor forays and bits of research for the waves of scenarios I never expect to actually make in full, I’ve found one year where I view the most interesting, novel alternate history scenarios as no longer being possible.
1965.
It’s a pretty sudden cutoff. I think the two big reasons are:
Vietnam
The units involved in the Vietnam War are so well-known that they cease being novel. The F-4 is a lot more famous than the FJ-4. Because 1965 marked the beginning of high-intensity air operations, it fits with the 1965 date. But Vietnam is actually the junior partner here. The bigger reason is…
A paradigm shift in military procurement.
The 1950s were a period of ultra-rapid progress, a sort of “Moore’s Law For Jets”, of rapid obsolescence, high accidents, and the fumblings of any infant field. For non-aircraft, it was less pronounced but still there-as shown by the mix of WWII ships and the very first guided missile vessels that made up the US Navy.
After that, as I mentioned in an old post on the F-4 itself, you get in the missile age (in an oversimplified but still generally accurate way) long development times followed by long service times, with the systems on the platform being of more importance than the platform itself. The last F-4 rolled off the line in 1981, its production lasting longer than the service of many mid-50s fighters. Throughout that time it had gone from a naval defense fighter to a multirole champion.
So what this means is that pre-1965 alternate history scens have more inherent variety. The airwing on the CVA-14 Ticonderoga during the 1958 Sumatra crisis (to give one example) can be substantially different from one on a similar ship several years earlier or later. This is not so dramatic in later decades-they change, but not to that degree.
This does not mean that post-1965 scenarios can’t be novel or interesting, only that the 1953-1965 period has a sort of maniac charm to it that later ones don’t have.