Specialized tooling is hard to make. For example, Russia is currently suffering from a reduction in railway capacity as they are unable to make some types of re

Specialized tooling is hard to make. For example, Russia is currently suffering from a reduction in railway capacity as they are unable to make some types of replacement ball bearings for rail cars, and they are also unable to make the devices for manufacturing them. The world is quite interconnected, and if you can buy a rare component at a good quality and price whenever you need one, then bootstrapping an industry for that doesn't make sense - since you alone anyways won't have the scale required to be cost-effective for it.