Incapsula lets you block all visitors from a specific country.
In order to achieve this:
1) Go to your site’s settings screen in the Incapsula console and click on the Access section.
2) Choose the countries you would like to block visitors from, either via that interactive map or by checking the country list.
3) Whenever you select on a country, it will appear in the selected countries section below the map.
4) When you are finished, click Save.
Why would you want to deny access from a certain country?
It is common practice to block countries from which many attacks are executed. If visitors from a certain country are not part of your target audience you might want to completely block traffic from that country.
Doing so will also remove all the unnecessary “noise” from your website analytics tools due to all sorts of unwanted visitors from the blocked countries.