From Leupold's website:
"Leupold uses foreign sourced components for some parts of Golden Ring products, primarily lenses. This is because at this time, there is no American manufacturer that can supply the quantity of high quality lenses that Leupold needs for its annual Golden Ring Optics production. Leupold’s lens systems are designed at Leupold, by American optical engineers, in its state-of -the-art optics lab and then procured from outside vendors who must meet stringent quality standards.
Incoming parts are carefully inspected in our testing facility before they are accepted into the assembly process. Incidentally, all major optics producers worldwide acquire some or all of their glass from the same sources as Leupold. Some of these sources are located domestically, some are European, and some are Asian. Leupold has acquired its lenses this way for over 50 years."