about 100 miles
West
There is sea on the east side of Argentina. Uruguay borders to the north east.
Chile is a country that is longer north to south than it is east to west.
The United States is about 2,680 miles wide from east to west.
Australia is approximately 2,500 miles (4,000 kilometers) wide from east to west.
Peru on the north, Argentina on the east and Bolivia on the northeast.
4850km
99
Chile is a long narrow country. If, by "left to right" you mean west to east, then you are measuring its WIDTH, not length. It is roughly 250 miles west to east, but over 2,000 north to south.
Panama.
From East to West in a straight line, Iraq is about 810 Km wide
Kansas is about 400 miles wide from east to west.