Gdddk

Looking for the name of a country.

_{This puzzle is part of Recycling old answers.}

I think the answer is

Cote D'Ivoire (or possibly Ivory Coast to fit with the overall meta-puzzle)

Reasoning

This is to do with flags.
If you take the first part of the flag of Nigeria and the last part of the flag of Peru and combine them, you get the flag of Italy.
Similarly, if you take the second half of the flag of Sudan, reverse and copy to the first half, it becomes the flag of Yemen.
If you turn the flag of Ireland upsidedown, it becomes the flag of Cote D'Ivoire.

The answer is

ICELAND

Reasoning:

1. 
   

   
   
   This is a mix between Nigeria and Peru. Notice how they are mixed such that the E and the R are joined together by a line. This is significant because when you join Nigeria and Peru with a line, you cross Liberia. These three countries have a common infix: er. Now form a triangle with corners Nigeria, Peru and Italy as located on a map, and you get that this triangle contains the Mediterranean Sea, also having er.

   
   

2. 
   

   
   
   This has a mix of DAN reflecting each other from the straight line of the D. dan is the suffix common to Jordan and Sudan. They are on opposite sides of the Red Sea. Since we are talking about suffixes, a suffix of Red is d, which is where we are reflecting from, causing symmetry $rightarrow$ sea-mmetry. If we draw a triangle with the corners Jordan, Sudan and Yemen as located on a map, our triangle contains the Red Sea, with its common properties.

   
   

3. 
   

   
   
   This is Ireland upside-down and back-to-front. We know that there must be another country hinted, and from the previous two points, the country we want to find out is a third one such that if we form a triangle with all three countries as corners, it contains a sea, and this sea must have a common property with all the countries.
   
   Next to Ireland is the North Sea, written in such a way where "North" is written above "Sea" on a map, and "r" is above "e". If we read this up to down (which is why Ireland is "upside-down") then we get re which is an infix also belonging in Ireland (and the Red Sea). Now notice that if you put every upside-down letter in IRELAND in the question and rotate them back to normal, you would be reading IRELAND backwards. We have to switch sides and read it from the other side. Likewise, if r and e switch sides, they make er which is in Germany. This is our second country.

   
   

Therefore,

The third country is the last corner of the triangle that must contain the North Sea, and must relate to what we are talking about. This country is ICELAND. It fits the first part, and we are talking about opposites — upside-down, switching sides, etc — and Iceland is land not covered in ice: an opposite! The vikings named it Iceland in order to trick their enemies to not go there to steal their good green land (making them go to "Greenland" instead, which actually was, and still is, full of ice).

And the final question:

Why are the letters E and R so important?

Because...

This puzzle is part of the Recycling Old Answers meta-puzzle :D

Here is a map for reference: