Remember Zaonia (0104 C885655-5 Ag Ri 123), the little planet that could? Zaonia had instituted a system of handwriting analysis to prevent fraud in its starport. The planet had created a secure system of banking that its more populous and advanced neighbors envied and made use of. It even had a small fleet of free traders operating in its cluster.
The Zaonians were secure. The dictator of Facesos, the ministers of Inerze, the recluse roboticists of Zerar were all customers of their banking system. Anyone invading and disrupting the security of their valuables would face their wrath.
ThePrince Admiral of Facesos, the plague ministers of Inerze, the recluse roboticists of Zerar didn't give a deuce about the fate of Zaonia, just the security of their valuables. A change of power that did not endanger those valuables was no concern to them.
So when a young technocrat, one who had spent much of his life offworld, decided to make a push for power he first assured those offworlders he would respect their property (and in fact give them better rental rates on vault space). Needless to say he told them this at about the time his offworld mercenaries commenced to land at the starport and major cities.
The usurper was on a budget so battledress troopers were a small minority who seized the starport and secured the communications. The rest were troops with cloth armor and laser rifles who expected to wage a quick and relatively bloodless campaign of shock and awe.
The poor bastards. In his years offworld the power monger had learned a little about high technology weapons. He had forgotten all about low technology warfare and that was his downfall.
Now maybe the Zaonians could not build one radio jammer that could follow enemy chatter across many frequencies, but they could build a lot of jammers and keep them hid away (remember all those tunnels they dug for the banks? As for their forces, they used telephone lines and signal flares and carrier pigeons in some cases.
Maybe they didn't have the camouflage armor and orbital sensors the invaders had but they had an elaborate tunnel system which they used to mount a series of counter attacks on the starport. When the battledress commandoes descended into the tunnels to root the locals out they faced a storm of heavy machineguns, flame throwers and demolition charges. The last straw was the armored cars the Zaonians had in the tunnels to transport valuables. It turned out bullet proof didn't mean you could laugh at an armored car parked on your chest. They mutinied about the time they figured that they would run out of commandoes long before they ran out of tunnels.
On the surface the invaders now faced an artillery bombardment that turned out to be sand canisters modified to fire from field guns. Their laser weapons were now degraded so badly they had a third the range of the rifles the locals carried. The invaders did not have heavy weapons. The usurper didn't want to wipe out the planet he'd rule and well, he did have those pretty lasers and battledress commandoes!
The usurper discovered the sand canisters were fired from a couple of destroyers off the coast. He demanded the landing craft commanders go airborne and shoot the destroyer up. The commanders, having seen the way the invasion was going stuck to the letter of their contracts and said 'No!' That turned out to be very fortunate for them as they would have met the submarine with the offworld missile turrets (that was still very hush hush.)
Okay he tried to tell everyone the other Tech Knights had used offworld munitions. The sand canisters were a starship's weaponry for gosh sake! The Knight Senior explained it away as a naturally occurring crystal, not manufactured, merely polished. What the heck. They played fair (so to speak) with all other tech. The submarine with the missiles was still a secret.
The Zaonians then turned to their depositors and explained that the rates were going to stay the same.
No harm, no foul. The customers merely had stayed out of an internal dispute. That was fine. Zaonia was an honorable society. One less than honorable might put photocopies of a number of sensitive documents they were entrusted with onboard their small fleet of freighters to distribute to several interested parties should anything happen to their government. The offworlders thought copying documents required a computer. In fact carbon paper astounded some of them when they came visiting.
As for the starport and capital that took a little repair work. It was awhile before they took the shot up and mangled battledress suits off the perimeter wall. they wanted to make sure people got the message.
Better Low Tech than Dim Wit.