> What is the BOM for the challenger tank - how many chips in there that are made by whom

In today's world, it would seem more sensible to just stockpile enough of all the components for 5-7 years of tank production, knowing that if your enemy tries any evil tricks then you have half a decade to figure out how to redesign or make the components yourself.

Keep a close eye on anything that looks like an antenna and it isn't so bad having the enemy backdooring your chips either.