Treating ST tires properly is more important than where they're made and internal heat buildup is the #1 killer of them. Never tow under-inflated, overloaded and/or over their speed rating. The higher you can make the reserve load capacity, the better too - should have at least 10-15% and by upgrading to LRD, we have about 30%. Some TT manufacturers install tires with very low reserve capacity but unfortunately there are no rules against doing that. Other things help like checking psi regularly, staying off road shoulders, avoiding sharp speed bumps & potholes at speed, don't curb the tires, use covers to reduce UV damage and replace tires at a pre-determined age (recommendations vary at 5+/- years) even if they look new.
People can say their tires exploded in just a few months and claim that they treated them properly and therefore it's because where they were made. But you will never, ever know the true history of how they were treated so can't correlate it with country of origin. If there was a rash of failures with the same brand tire that's be different tho.
When people buy towable RVs, who tells them the importance of treating them correctly? Not a dealer, that's for sure. No sticker near the tires anywhere. Nothing in an owners manual. Ask around a CG and you may find many haven't checked tire pressure since they bought their camper. One of the best places to get RV tire info. is RVtiresafety.net, a blog run be a retired tire engineer.
The new GY Endurance tires sound like a good bet and are what I want to install after the end of this season when our Marathons will be 5 years old. But they look almost new (sniff, sniff). :(
Then there's the crowd that says LT tires are the only way to go.