After sales support for aircraft between different manufacturers/countries

Starting from 1980, how have various manufactures faired in after sales support. Of course spares, training, etc almost always involve politics, so it should also be factored in.

This may be a sensitive subject but I’m hoping it’ll be an interesting discussion.

some things I can think off (which may be inaccurate):

Lockheed-General Dynamics/USA: Pakistan had some difficulties with their F-16s after an embargo, but it seems that after that has been dropped, support and service from the US has been reliable.

Dassault: reliable, but I’ve heard their spares and support are very pricey. I haven’t heard too much in terms of the French government limiting support or sales but I have heard that they are willing to let nations opposite of their customers, to inspect their aircraft.

Sukhoi/MiG/ Russia: lately I’ve been hearing that there’s disputes over contracts, schedule and payments (after reading whats happening on the Gorshkov which is a ship not an aircraft, etc)