Fact of the matter is, the days when a handful of (mostly American and European) companies could dominate the manufacture of complex equipment are long gone. Most countries that can afford trains - but also things like aircraft, road vehicles, ships, machine tools, and so forth - expect to build them locally. For exactly the same reasons that we expect that in the UK. And they mostly have the money to be able to afford to do so.
All of which is to say, even a successful industry is going to see dwindling numbers of export orders. There might be small quantities here and there up for grabs, but they're always going to be a nice bonus compared to domestic orders.
Globally, there are 2-3 aircraft manufacturers (Boeing, Airbus, Embraer) and engine makers (GE/Snecma, P&W, RR).
Many significant countries do not build aircraft or engines (except maybe under licence).
Some countries have quite large component specialisms, with the UK having wings, engines and landing gear instead of complete aircraft.
Airbus uses some Boeing components, and Boeing uses some Airbus components.
Rail equipment is going the same way because the technological advances require massive investment to keep up with the competition.
Assembly can be devolved locally, but design is centralised with Siemens, Alstom and Hitachi currently dominating design.
Again, other companies can offer component specialisms, including brakes, power equipment and interiors, which is where the UK is now.
CAF EMUs from Spain (or Newport) come with Austrian traction packages.
Nationalism doesn't work when Hitachi AT300 bi-modes are powered by MTU generator packs made in Germany by a Rolls Royce company, and serviced in Derby.
The rail supply chain is global (and I've not even mentioned China).