ELECTROMAGNETIC BOMB!!

These weapons are not directly responsible for the loss of lives, but can disable some of the electronic systems on which industrialized nations are highly dependent.
Devices that are susceptible to EMP damage, from most to least vulnerable:
Integrated circuits (ICs), CPUs, silicon chips.
Transistors and diodes.
Inductors, electric motors
Vacuum tubes: also known as thermionic valves, shielded gold-coated tubes can often survive substantial EMP and are commonly found in older "hardened" electronics like MIG fighter jets' control systems. These may still fail (statistically rather than predictably) due to induced parasitic resonance among other things.
Older solid state components are more likely to fail and late-generation milspec vacuum equipment is more likely to survive, although in military EMP tests, the solid-state PRC-77 survived testing while the hybrid PRC-25 suffered failures in its tube final. Different types of tubes, transistors and ICs show different sensitivity to induced current spikes; bipolar ICs and transistors are much less sensitive than FETs and especially MOSFETs. Older high-power tube radio circuits may fail due to vaporized welds or spot-heating of some conductive element that happened to be resonant at a harmonic of the frequency of the pulse. Late-generation milspec tubes are better-designed and more rigorously tested to minimize EMP vulnerability, but are also usually smaller and more likely to be resonant at frequencies where substantial pulse energy is present. Most modern military communications gear is extensively EMP-hardened and tested. Late-generation military tube gear was often fortuitously resistant, rather than reliably resistant; EMP effects were not well understood until the late 1980s to early 1990s. Prior to that, EMP-hardening was mostly a matter of ad-hoc overbuilding rather than nuanced understanding of vulnerability.