All US army supercomputers are Lenovos, all components in all systems since 2005 are made in China.
Hell for some even master series are made in China.
Nearly the entire production of US electronic hardware, including military ones moved to Asia as soon as the mid-1990's.
Currently there is no USAF/NRO satellite getting in orbit without Russian made engines.
It's not THAT far fetched, of course the reason for this is that the cold war was over and the shift in what was considered Strategic National Interests.
Also weird shit happened even during the cold war, like nearly all advanced US planes (B-2, SR-31, etc …) used titanium alloys made in the USSR (since they were the only ones making enough), the CIA mounted a whole hidden program to supply the thing to deceive the soviets (which would never had sold them otherwise).
So yeah if NK was making amazing tech somehow and was willing to sell them in a context of far less tensions in the cold war… it could be "far fetched but believable"…
Of course it wouldn't need to be a built in kill switch or something equally retarded, but for example jamming frequency exploitation (if you precisely knows the components/tech specs of a system, then it becomes easy to jam, even more so if you created a flaw in the first place… That's what EVERYONE selling arms does BTW. France is still in trial with Argentina for giving UK the proprietary jamming frequencies of the Exocet missiles, which UK asked for after Argentina initial success during the Falkland war. France and UK being allies they released them. And suddenly the Argentinians couldn't hit for shit…).
Of course I'm pretty sure that's not how they explain this and just go full retard.
But it could be made without breaking the suspension of disbelief, (like the WARPAC crumbles in civil war in the end of the 60's, instead of rapid pacification, many socialist factions are essentially fighting each other in a redo of the Russian Civil War just bigger, NATO stays out of it for fear of nuclear retaliation, since every nutjob has some, EEC construction get a real defense with continental states leaving NATO, since the USSR is not that threatening now, prompted by De Gaulle and the newly reunited Germany…, China + Nork take over the leading role of the commies block and but after the vietnam war appear to reject direct confrontation with the west and in appearance seek reconciliation with the US instead, etc…)
But yeah there is no way they did that…