A criticism often brought up in many 1980s WW3 TLs is that by the mid to late 80s a Soviet conventional victory is implausible - that their troops lack morale and discipline, and their Warsaw Pact allies are on the verge of revolt, and that
With that in mind, what is the latest date that the USSR can secure a conventional victory in World War III - defined here as controlling Europe up to the French border and keeping their own borders secure in the East?
Scenario 1 assumes no China combat role; Scenario 2 does. Assume no nuclear usage.
For Scenario 1, at least, I would put the date somewhere around 1979 - early 1980, prior to the deployment of Pershing II and the GLCMs and the development of AirLand Battle in 1982.
I am by no means an expert or even that well-knowledged, so please correct me if I’m wrong. I assume Solidarity in Poland could still cause trouble for the USSR in this scenario.
Problem is that both listed limitations are unlikely to the point of impossible without some significant alteration to OTL, especially since they need to both be in place.
Looking at the POTUS alone indicates the Difficulty
1. Truman. Distrusted the Soviets with a passion, seems to have despised Stalin. U.S. WMD use was a given in any serious conflict in Europe and everyone knew it. The Soviets, moreover, have no real ability to respond in kind.
2. Ike. Could read the relative ToE. Retained a close to monopoly on deliverable weapons to the enemy's homeland virtually throughout his term. Wasn't a beginner at spilling blood across Eurasia in defense of the U.S.
3. JFK. Much more of a hard case on Defense than sometimes believed. Did deescalate Cuba without going to war. Was cocked and locked just in case.
4. LBJ. Looked reasonable compared to Goldwater (Sir Arthur Harris would have looked reasonable during that campaign).
5. Nixon. Man went to DEFCON 3 over Soviet statements regarding intervention in the Yom Kippur/October War. Literally bombed his way out of Vietnam (one of the oddest way to make peace, especially for what amounted to the losing side, ever). Imagine what he would do if AMERICAN troops were getting rolled up by the USSR.
6. Ford. Combat veteran. Pretty conventional GOP politician (i.e. staunch anti-Communist).
7. Carter. Ya, I know. Still, Canoe U grad, nuc at that. might be the least likely of the group, not that he was all that unlikely.
8. Reagan. Just start digging holes.
Moreover, throughout the mid 60s-1970s it was an absolute given that any war in Europe was going to feature heavy WMD usage. NATO commanders knew that they forces on hand, minus a long build-up, couldn't hope to hold the Fulda Gap. Way too much of the active duty U.S. military was pointed at Southeast Asia for it to go any other way. The Soviets, by all accounts, intended to use CW almost from the opening salvo which would trigger the NATO WMD=WMD policy.
Between 1965 and 1990 the PRC has been hostile toward the USSR/Russia in varying degree. It was 1991 before the Sino-Soviet Border Dispute Agreement was hammered out (even that agreement sort of contravenes the oft-states CCP mantra of brings ALL historic Chinese territory back under Bejing's control. A USSR that is hip deep in a war with the West would be ripe for the plucking.
However, putting all the above aside, the best chance for the Soviets would have been 1947-52 and 1975-1981. U.S. force levels were minimal in the late 40s-early 50s, everything was built around the nuclear umbrella (during the early part of the Berlin Airlift the U.S. only had two fighter squadron in Germany proper) and under 40 of the "Silverplate" modified B-29 were available in total (none in Europe). The other side of the coin is that the USSR was pretty much a basket case post WW II and wasn't in a position to push too hard.
The U.S. military was in pretty crappy shape post Vietnam, lousy morale, discipline sucked, and the "all volunteer" force was just starting to be created. WAY too much money had been spent, and too many training hours devoted to, small unit and jungle training during Vietnam. Both the Air Force and Navy were in transition from the Vietnam era F4/A7/Century Series into the far more capable Eagles, Tomcats, and Vipers.