Zeiss lenses are made by Schott Glass, a subsidiary of Zeiss. ALL Zeiss scopes use Schott-manufactured lenses of some sort, so the quality is outstanding. Zeiss is one, if not the only, manufacturer that makes it's own lenses. Swarovski may as well, but I am not sure--is Swarovski worth it though? Most of the land-based telescopes in the US use Schott-made lenses of some kind.
The tubes for the Conquest line are made in the US, but the other components are made in Europe and imported into the US. The cost of labor is less expensive here; therefore, the importation of components for final assembly of the Conquest line.
Additionally, Zeiss etches the reticle into the lenses. Most other manufacturers use a reticle made of wire--another component to assemble. It's not likely that you will ever break a reticle made by Leupold, as an example, but it's just another feature to point out.
If you own a Zeiss scope, you own a quality product.