This is super common with industrial espionage. As a reductio ad absurdum after 1991 I believe the Russians sold working fighter jets with detailed blue prints and instructions on how to manufacture all the components to the Converse Chinese. They still failed to make a perfect copy. Same deal for whatever the Soviet copy of the B-52 was. Building a sophisticated piece of machinery when your supply chain is very different you have to make compromises and different choices and they all add up.

This sounds rather absurd given that preparing a space shuttle for launch takes literally months. But the idea was, as far as I can tell, that it would launch on a regular mission, then use its heat shield and aerodynamic surfaces to change orbit inclination radically while out of reach of soviet radar, resulting in totally unexpected direct overflight of Moscow, making a decapitating strike possible.

There was industrial espionage too. Considering they had the former and political backing, it's surprising how much of a disaster the 144 was - Not least because it was built for a market that didn't exist (comrade) in the Soviet Union, it was a noisy deathtrap. Their western equivalents flew somewhere on the order of a thousand times further (Concordski only did about 100 commercial flights)