Why not?
This is the exact model in which WWII operated. Car and plane supply chains were practically nationalized to support the military industry.
If drones, surveillance, satellites become the main war tech, they'll all use silicon, and things will be fully nationalized.
We already have all sorts of hints of this. Doesn't need a genius to predict that it could be what happens to these industries.
The balance with food and fuel is more delicate though. A war with drones, satellites and surveillance is not like WWII, there's a commercial aspect to it. If you put it on paper, food and fuel project more power and thus, can move more money. Any public crisis can make people forget about GPUs and jeopardize the process of nationalization that is currently being implemented, which still depends on relatively peaceful international trade.
> Why not?
Bombs that fly between continents or are launched from submarines for any "big scale" war.
CPU and GPU compute will be needed for military use processing the vast data from all sorts of sensors. Think about data centres crunching satellite imagery for trenches, fortifications and vehicles.