BTW--I added the qualifier "in combat" deliberately. 1972 was a very different situation from today. Back then our aircraft flew all kinds of sorties against operational SAM systems--so our intel was very good. SAM technology was a lot easier to spoof back then, but the NV operators were also highly experienced. Luckily, the BUFFS had Wild Weasels to help with SEAD. Even so, there were BUFF losses; they were far from invulnerable.
Of course, EW defensive systems are kept up to date. But they are only as good as the intelligence and exploitation available--and those are never perfect. In Schwartzkoph's autobiography ("It Doesn't Take a Hero"), he made the comment that B-52's were invulnerable due to the EW packages. If someone told him that they were either naive or lying. Lucily, Sadaam mostly had the older stuff.
EW countermeasures are just a part of a package, including SEAD and tactics. A smart crew views them as a tool of last resort--nothing more.
The B-52s back then were awesome in their EW not so much because of flying against operational SAM systems (there was some of that); their EW systems were already pretty much “set” before the time of Linebacker 2. No, they were good because they had been designed and then practiced to penetrate the Soviet Union, and there was no doubt in my mind that they would have reached their Russian targets. The BUFF losses were not in the least due to any lack of raw EW power, which is difficult to describe fully, but because NVN was able to use the certainty of B-52 timing and altitudes of the all too predictable ingress and egress, firing dozens of missiles to detonate at the right altitudes and coordinates. The radars and missiles were absolutely not able to function normally in a predictive sense.
As far as Sadaam having the “older stuff”, the B-52s also had EW upgrades for the “newer stuff”; it really didn’t matter to the B-52s, they were loaded for bear.
EW countermeasures a tool of last resort? Maybe for a fighter, who can use evasive maneuvers, but this is simply not true for the B-52. SEAD? B-52s were designed to penetrate the Soviet Union, and guess what, there was not going to be SEAD on that fateful day.