APA: Ground-based counter-air ECM systems
Air Power Australia has a handy overview of ground-based counter-air jammers developed by the Soviets & WP states (including the infamous SPN-series “Heart Ache” truck-mounted kits).
These systems would have been critical in any WW3 scenario (just imagine drastically cutting the practical detection range of NATO’s AWACS aircraft) and continue to be valuable assets for disrupting the C4I/ISR network of any sophisticated adversary.
Hat Tip: ELP