there is no correlation between country and weather or not you can beat them. it's rating not nationality.
What nationality is hard to beat and what are the easier ones to beat??

Indians are hard to beat..Chinese,Vietnamese,Singaporeans play very fast..Malaysians and Indonesians are very patient and always strategize hard.

players from the Philippines are the easiest to beat.
Well for me there are easy to beat and there are those that hard to beat..Back when i was 1500 below there is always that player from the Philippines that beats me when i'm having winning streaks.

Pakistanis are easier to beat I think with their impatient moves. Those from Central Asia are hard to defeat.

id say nations where other board games are more widely played , but certainly countries where little chess is played

For me, its rating that correlates with opponents and in the team games I'm in where there might be 100 games between 50 pairs of opponents, no matter whether my team is playing Team Moscow, Team Alabama, Team Argentina, etc. the results average out to what you would expect from the rating differences.

Indians are hardest to beat. Americans are easier to beat.
That's just the average, in my experience.
Canadians are fun to play, and usually open to a bit of chat, in my experience.

one thing though is chess is a two way thing , if either of you go before move 1 oh no i always lose to (insert flag here ) then its not good mental preparation to overturn past results
try "oh good your flag again right round 2 "

Ive only beaten an indian player ONCE, thats it, i dont know why they're so much better on average. every single one ive seen is atleast decent idk why
Its a timezone thing I think , depending on the time of day you get different nationalities playing , it tends to be harder to gain rating when playing in Indian peak time than USA peak time, it is quite possible therefore that their ratings are not equivalent.
No anti-nationalism ..just curious.