Also the fab for a 20year old process is probably easier/cheaper/faster to re-build in case the enemy destroys it, than the fab for 5nm process you've been buil

Also the fab for a 20year old process is probably easier/cheaper/faster to re-build in case the enemy destroys it, than the fab for 5nm process you've been building for 4 years. 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.