I have world destroyed by a war, but still on certain level of technological advancement. The basic thesis is that due to technological advancement of warring nations the people came up with lasting EMP field to disable advanced electronics for prolonged time. Soon after, every battlefield was EMPed once one side started loosing to disable enemy tech and had a chance to rally or retreat. And it did not take long time before battlefield was just preemptively EMPed (just to be done with it and prevent enemy to fire EMP on their own terms). After some time, EMPing of cities begun to cripple production and demoralize population. Soon these pulses covering almost every part of planet except underground part of cities build like Faraday cages for HQs, science labs and essential factories and of course private Faraday villas for rich.
Some things I struggle with and I would like to be corrected if wrong:
Armies have reverted to Firesticks (demeaning name for concurrent powder weapons) from Emguns - hand-waved infantry sized railguns. Problem is, soldiers still have futuristic armor which was fair protection against Emguns but against Firesticks it is almost impenetrable. Except for really close range (below 10m with AK or SCAR), concentrated fire or special sonic AP ammunition which can be fired only from what is basically Barret M82 and other current high power weapons - basically impractical guns for infantry use. Armor covers almost whole body except joints and face.The kinetic energy is still noticeable, but wont cause any serious blunt trauma. Concentrated fire against one armor segment would overwhelm ability of segment to neutralize kinetic energy until the point of shattering (it is unobtanium non-newtonian liquid getting hard during impact)
My hypothetical change of engagement tactics: The engaging squads would use smoke grenades to cover themselves from Barret Snipers and generally to close engagement distance safely under 10m for "easier" incapacitation. But whole combat would be really messy since nobody would see. Another idea I have that whole combat would look like Mad Max where Squads would fight in some Hum-wees, peppering each other with Miniguns and RPGs in high octane combat, but those are really ammo hungry and I somehow doubt they would achieve anything before returning home with empty magazines. So I am not sure about it.If you have more plausible idea please share with me.
Would air-force revert to world war 2 style planes and bombers (but modernized - better engines, better guns)? Were cold-war/vietnam war jets enough "primitive" to be functional under EMP pulse?
Thank you all for answers, feel free to answer any point of the three you want. Or all. Also sorry for my weird English, I am from Russia and I still struggle with English.
Edit note: I simplified question on pure military engagement