I think a "Cold Warriors" line would be intriguing - there are all sorts of real conflicts that era covers, and there are alt-history type conflicts that would work such as a "Red Dawn" or "The Day After" scenario, and then there are sci-fi possibilities, such as Cold Warriors vs. Zombies (Aliens, Pod People, etc.)
That's a great point about '60s/'70s era military uniforms, gear, and weapons doing double-duty as '80s era National Guard - and it also works as civilian miltias, guerilla armies, and so on from the '80s to present (I'd venture to say there are lots of American survivalist/patriot types who have all sorts of Cold War military surplus stuff... even I've got a Vietnam-era AR-15, SKS, and AK-style rifle in my gun cabinet, and guns from those eras are popular with lots of American civilians.)
Similar to Twilight 2000, I've said before - and I'm more than half-serious - that Cold War-era armies can be souped up into a "G.I. Joe vs. C.O.B.R.A." style imaginary/alt-history/quasi-cyberpunk conflict: kitbashing Cold Warriors with, say, the Cannon Fodder, WWII Germans, and Death Fields accessories would give the mix of retro-'80s and quasi-scifi elements that would fit right into this sort of thing... just add some souped up 1/48 scale model Cold War military vehicles (which, I believe, are still pretty easy to find, and are "close enough" to 28mm scale to work!) Really, I'm surprised the IP holder (Hasbro, I believe?) hasn't published a wargaming rules set for this sort of thing - its time has come, and maybe they would be willing to consider licensing actual Joe vs. COBRA wargaming miniature kits for use with such a thing, though I'm just fine with more generic homebrew stuff - I've not seen the "0200 Hours: Night Raids in WWII" rules yet, but something tells me those would work great for this sort of thing as-is, or at least with minor tweaking to update to '80s quasi-cyberpunk :)
With all ofthe above in mind, a "Cold Warriors" line probably should include local "civilian" militias from around the world, for post-apocalyptic gaming, zombie survivors, "asymmetrical warfare" conflicts, "Red Dawn" scenarios, and so on. (Restrained, generic '80s era civilian costumes, carefully selected, can cover a great deal of 20th and 21st century history: variations on a basic jeans-and-Tshirt outfit covers the '60s to present, for example.)
In any case, some of the obvious (and many not-so-obvious) armies for this era (in no particular order) could include:
- Cold War USA
- Cold War Soviets
- United Kingdom
- generic NATO forces / UN "blue-hats" Peacekeepers
- generic Warsaw Pact "Ruritanian" forces
- North Vietnamese Army / Viet-Cong (at a glance, I think the same kit might work for both, given options for their different weapons and other gear?)
- generic Middle-Eastern, and/or a weapons sprue to update the WA Afghans for this era
- NATO and Soviet-Bloc soldiers in "NBC" suits (Nuclear, Biologoical, Chemical protective suits)
- generic American/European Cold War "civilians" with weapons (shotguns, hunting rifles, handguns, molotovs, baseball bats, etc.)
- Accessory Sprue of popular Cold War small arms (mostly M-16s, FN-FALs, and AKs, plus SKS, M14s, Uzis and Skorpions and other SMGs, M-1911s, RPGs; plus gear like radios, binoculars, night-vision, geiger counters, etc.)
- the living dead
- Thugs and Hooligans (post-apocalyptic biker gangs and the like - see "Dawn of the Dead", "Mad Max", etc.)
- SWAT / Special Forces set
- "Death Fields" accessory sprues and other bits can update many of these sets ino vaguely cyberpunk territory, in addition to converting them to "Death Fields" factions.
- Yesterday's cutting-edge military gear and uniforms become today's mil-surp leftovers for the National Guard and/or civilian militias, rebel forces, etc. - these "Cold Warriors" can be used as such in wargames set in the 21st Century and beyond.
- Spare WWII weaponry and gear would probably fit right in on at least some of these factions for early Cold War armies, mercenaries, special forces, reserve and auxilliary forces, etc.