Can you buy a non-China bomb tire for a trailer?

The 13" part is likely your weak point. If you changed to 14", you could get Goodyear Endurance. If you could go all the way up to 15", you would have a lot of options in an LT.

I know people beat on Chinese tires regularly, but I have had Marathon's that were made in both the USA and Canada blow out just like everything else. That said, I put Endurance on my boat trailer, and it handles significantly better than with the non-name brand that were on as OEM.