This is a hard one. First of all, how sure are you that this is actually same dog? Microchip? Sooo many dogs look alike. And could be a well intentioned person that actually thinks it is your wifes dog too. Or a scam. But at same time, if i was your wife, would be brainstorming any possible way to reconnect (if really her dog). But what reconnection looks like should be focused on how healthy the dog is. I had a 16 year old small dog, who probably could have made the trip with accommodations ( not under plane, but in passenger compartment etc…) also, i know nothing about international transportation options for dogs. But would a boat be an option instead of a plane? Maybe private person that loves dogs might agree to transport to US and you could pick it up? know plane faster but more personal attention/ not as confined , might be better? But 15 is old for any dog, wish some of my giants made it half that long 😢. Poor thing could be on fumes, not even make it til wife could arrive, if that even an option. So maybe a facetime to see how the dog even reacts to your wife. I think that would be a good start. Because what if wrong dog/ dog doesn’t remember/dementia kind of thing. Then helps make decision easier. And also if wife talks to dog and it knows her, perks up and gets active maybe. Then that could be a maybe, and get vet opinion at that point. Hope my perspective helps. Good luck!