Have a look at what type of microchips are used in “cutting edge” military equipment like fighter jets. They are often decade olds. More speed is simply not important enough.
But if we were in desperate times, I think the limits would matter and fab tech would be an important strategic asset for what it enables. The nature of it is that its easier to attack, but we hopefully have something to defend.
Intrinsically larger process nodes are better for analog and have uses even as new fabs come along. In 7nm your analog signals are not treated very nicely, but these are important for sensors. Also power electronics are not really on the newest nodes either. The microchips are old because they get the job done and I don’t think we feel so threatened to push the limits.
Nevermind the nation probably has more than 1 of such old fabs, so it can't be technologically decapitated by destroying a single precious 5nm fab it has.
Imagine if the situation is missile defense, both the missile and the defense systems are computerized and not only the milliseconds but also the microseconds are the difference between a hit and a stopped missile. Whoever had the newest fab node would have a notable advantage in being able to push their system harder. It could be better ML in missile to lock on and dodge, vs the defense system predicting paths as fast as possible with as low latency as possible to defend a ship or similar asset.
Its asymmetric in the example of course, but both sides would be doing both shooting and defending.