You talk about military weapons for an imminent war, and then talk about how stock piling isn't sane business practice. These contradict each other.Jesus, have you paid attention to what’s happening in the world? US government has been trying to increase Patriot/THAAD/Tomahawk/AIM-120D/etc missiles productions for awhile now. European countries have agreed to increase their military budgets to 5% of GDP. Why the hell China would allow them to produce high tech weapons? The very weapons that are very likely to be used on China?
China has already banned quite a few rare earth elements, the latest move simply expand to more. There isn’t likely to be stockpiling because no sane businessman like to keep a huge inventory.
The rare earth card is a one-time-use card. It is not a leverage. Continuous supply for civilian use is.
The military doesn't care about "sane business practice" in a scenario of imminent (next few years) war. They will stock pile what they need. They will accelerate reopening commercially intractable refineries. They will do whatever it takes to wrest rare earths from their allies' supply chains. Industry won't do this, but the military will.
Giving the US a grace period of a month to order as much of the newly restricted rare earths as it wants, doesn't make sense if it's about delaying US military action. We can agree to disagree about this though, and just see what happens next.