The 3 snipers with the most confirmed kills in American history are
Here are some examples of other snipers with higher totals
Canadian:
Francis Pegahmagabow (WW1) credited with 378 kills, and an unknown number of unconfirmed kills.
British:
Unnamed Royal Marine corporal (Afghanistan, 1 tour) 173 confirmed kills
Chinese
Zhang Taofang (Korean War) 214 confirmed kills in 32 days
German
Matthaus Hetzenauer (WW2) 345 kills
Josef Allerberger (WW2) 257 kills
Friedrich Pein (WW2) over 200 kills
Bruno Sutkus (WW2) over 209 kills
Finnish
Simo Häyhä (Winter War) 505 confirmed sniper kills of Soviet soldiers accomplished in fewer than 100 days
Soviet
Ivan Sidorenko (WW2) credited with over 500
Fyodor Okhlopkov (WW2) 423 confirmed
Semyon Nomokonov (WW2) 367 confirmed
Abukhadzhi Idrisov (WW2) 349 confirmed plus unknown unconfirmed
Vasily Zaytsev (Battle of Stalingrad) credited with 242
Nikolay Yakovlevich Ilyin (???) 496 kills
Sri Lankan
Ranjith Premasiri Madalana (Sri Lankan Civil War) 180 kills
Considering how much the U.S. spends on it's military and how much the U.S. is involved in conflict, it seems like there should be a lot more American snipers with high kill totals.
Chris Kyle got his 160 confirmed kills over the course of 4 tours while a lot of snipers with higher totals got their total during a single tour of duty.
I am not trying to glorify these deaths, but I am just curious what circumstances have prevented the U.S. from having more prolific snipers.
At least two things to consider are:
A) The nature of the wars. A lot of those non American sniper tallies were achieved during more conventional types of wars/battles/fighting, wherein you had large numbers of uniformed soldiers grouped in large masses, often with somewhat more predictable front lines.
B) Americans tend to try to rotate their units and personnel out of the front lines. So while he may have served four tours, he wouldn't have spent his entire time during those four tours engaged in actual combat. There would have been a lot of down time. And when he was "on the frontlines" or "outside the wire", he wouldn't have been fighting the same kind of enemy as in a lot of the other cases you mentioned.