The solution depends very much on your conditions.
If you have only a few country names you can create a table where in colm1 you write your country names and in colm2 you for each country the countif function using the specific country name in the argument and as the data range you use your entire column which contains all the country names you want to count.
If you have many country names you might better use subtotals. Once you have your subtotal you need to display only the subtotals. From there you can create your chart, showing the number of occurrences for each country name.