I don't know anything about the person you are conversing with so I'll refrain from positing on their origins or nationality, but plenty of American citizens have poor grammatical structuring skills; they would make the kind of mistakes you have corrected. It's not that uncommon, especially in the Southern states, like Virginia where I live.
Also, saying/writing USA, and I just did - as an American citizen
, is common too. I tend to say US or The States, and not USA, but there's plenty of people on either side. Some people go out of their way to say/write USA just to be patriotic.
Real Americans don't give a sh** about anything outside our borders, for the most part, and anyone who cares too much about the workings of another nation is either from that country - living in the US, or not being truthful about their origins. That's how you can tell us apart.
Oh, and I didn't read the rest of the thread and this is because? As and American I really don't care about India's dealings with France. Business is business.