Calvin Coolidge actually said...

I do hereby enjoin upon all officers of the United States charged with the execution of the laws thereof, the utmost diligence in preventing...

It would be quite a different proposition in selling a large amount of material that our Government thought it was expected might be used fo...

Any friendly government might request opportunity to purchase a few muskets and a few rounds of ammunition.

This is more a matter of domestic policy than the carrying on of warfare.