Frankly I wonder why do we think just coz we've achieved huge scientific & technological breakthroughs in missile & rocket tech or BMD or HGV or even CMs , other countries won't be able to duplicate what we've achieved TODAY IN SAY 2-3 DECADES.
Look at Australia . They don't have any mfg industry worth the name & they're a developed economy . Must be one of the few ones in the world as of today . They lack a domestic automobile or consumer electronics & / or durable industry or even a substantial mfg base yet look at the deep strides they've made in Hypersonic tech .
You could argue the US & UK are behind Australia & I won't deny their hand holding like we're seeing in the 5th Gen FA project between the US & RoK. But that doesn't take away from what both Australia or RoK have achieved .
I foresee Turkiye , UAE , RoK , Poland & maybe KSA pursuing such technologies achieving what we have up until now except the NGLV & Reusable SLV bit though I wouldn't put these specific technologies as beyond RoK .
Then there's Japan , Germany & Israel who're going to rearm in ways we can't even conceive of today.