> yet, they cannot replicate it, neither can Russia, heck Russia has these really powerful jet planes
Russia has powerful Soviet-era planes. Their new kit is demonstrably crap, being unable to establish even air supremacy against a foe wielding handfuls of decades-old air defence equipment.
There is also a P != NP difference between replicating a war machine and reverse engineering it sufficiently to defeat it, e.g. designing a radar that mitigates its stealth.
I can confirm, as someone who collects Soviet era electronics and buys replacement parts. Russian manufacturing is really bad now and very far from what it was during the Soviet era. Perhaps in part because of past cooperation between various countries of the communist block that is no longer there. For example Belarus and Poland made a lot of the integrated circuits(chips) back then. There are certain items, for example military radios like the R-140M almost every country had a local version of. For example the Russian version still used a vacuum tube as a delay timer well into the 80s while the Polish version had a box of digital logic.
Russia has powerful Soviet-era planes. Their new kit is demonstrably crap, being unable to establish even air supremacy against a foe wielding handfuls of decades-old air defence equipment.
There is also a P != NP difference between replicating a war machine and reverse engineering it sufficiently to defeat it, e.g. designing a radar that mitigates its stealth.