It's very rare that international relations get poisoned for generations without some ongoing work from both involved parties. Populations tend to forget things on the timeline of a decade or so.
The US can rebuild most of what they destroyed. It's gone now, and some of it they were already on the process of losing and can't get back. But no country is beyond reconstruction.
As someone who grew up in Russia in the 90s, that McDonald's actually did wonders! The problem is that y'all figured that if you help people who say that they are "democrats" maintain control over the country, it'll all work out, somehow. What actually happened is that many of those people were grifters, some others idealistic incompetents who thought they had all the answers after reading Ayn Rand. On the whole, the people - who were very enthusiastic about the changes in late 80s - by mid-90s felt like they've been robbed, quite rightly so (read https://en.wikipedia.org/wiki/Privatization_in_Russia for some examples), by people now firmly associated with the West and with words such as "liberal". This is the big reason why Western-style liberal democracy very quickly became a marginalized minority political opinion in Russia, and why the likes of Putin could easily take power by promising people that they'll fix the mess.
