They can buy a brand new truck sans engine and drop some terribly polluting piece of crap from several decades ago and bypass all modern emissions regulations.
The SCR/EGR/DPF regime that's been forced upon truck mfrs is at the ragged edge of reliability and maintainability, not to mention its effects on fuel use. So that regulators who've never heard of Pareto optimization can pursue cutting the final 1% of the emissions that a truck from the 1960s would have.
One badly-tuned mid-80s F700 can produce more particulates in a day than a brand-new diesel truck will in its lifetime, but somehow, the priority is not making it easier for the owners of forty-year-old equipment to update to the standard of...2004, but rather to decrease the number of milligrams per tank (at $infinity cost) of soot that a brand-new engine is producing.
Just look at the hole the US has dug for itself when it stopped producing civilian sea-ships, nowadays the cost of producing or even repairing its war-oriented sea-ships is way too high. And not only that, but it doesn't have the people with the knowhow to build those ships anymore, no matter the money thrown at the problem.
Western Europe has certainly lost the capability of making even artillery shells at scale, let alone tank tracks, just look where we're at it now.
> as military technology typically comes first before any civilian application.
Diesel himself wasn't involved in any military thing, as far as I know, so I think you're wrong on that one.
The thing is that without a strong civilian industrial base focused on things adjacent to warfare (like the steel industry when it comes to building ships or artillery shells) any big power is going to come very short-handed in the next big war (assuming the war doesn't get nuclear, which is another discussion). So, if your country can't make diesel engines at scale, for whatever reason, then you can say goodbye to your logistics lines because you need lots and lots of trucks for said logistics as part of a continental war, i.e. forget the tanks.
Must be due to the lack of demand for civilian artillery shells, right?
Otherwise good point.
Speaking from personal experience with a 2023 Chevy Duramax 3500, and a friend with a similar 3/4 ton Powerstroke.