Practically speaking the VVS would secure air superiority by striking every fighter base from Lakenheath to Ramstein with tactical nuclear weapons from TBMs, tbh, but that's a bit beyond the scope of Su-25. Its job would be supporting ground troops in their nuclear backed advance to the Rhine. Neutralization of the F-111s and the F-15Es in Lakenheath and Ramstein would be a hugely important operational-strategic objective to defend the strategic missile forces in Dombarovsky and other missile fields from being hit by bunker busters or something, which was a tremendous fear of the Strategic Rocket Forces and the General Staff.
A few thousand nuclear weapons can close a substantial amount of technological disparity since they're about two orders of magnitude more effective than conventional weapons and an order of magnitude more effective than PGMs. This disparity really shows itself when we compare attacking a hardened airbase, as only two or three nuclear weapons are needed vice thirty or forty laser guided bombs, or more.
Short of escalating to a strategic exchange it's unclear what the US would be able to do stop this as it simply did not view nuclear weapons in the same manner, and the Red Army would probably still come on top on that one, at least in Europe. This is not something the USA would be inclined to do though.
The VVS was ultimately more dispersed than the US European fighter bases so there were more nuclear targets to hit, yet the US had significantly fewer tactical nuclear weapons than the Soviets, and significantly more targets to hit. Besides that, the VVS also wasn't as instrumental to the Soviet fighting capability, with a greater emphasis on land artillery and long range missiles, whcih is partly why the DRA lasted longer than the RVN in lieu of superpower backing.
That said, I suppose the A-10s would make a valiant effort to take off before being hit by a few kilotons of ground bursts on their runway though. Maybe a few would even manage to get airborne.
Ultimately Su-25 was designed to fight a nuclear war on a nuclear battlefield and employ nuclear weapons in support of ground troops, and occasionally conventional weapons, such as laser guided missiles and bombs. It did this far better than A-10, which was stationed in a handful of bases in Germany in wing-size elements, and would have required a single battery of Okas to defeat. Given there were more assault aviation regiments, and the VVS dispersed attack aircraft by squadron in wartime, it's unclear how NATO would be able to gain air superiority by hitting bases, unless it attacked first with overwhelming nuclear firepower.
