May I suggest adding the option of playing with these rules that are based on a board game I used to play. These rules were a variant ot that game that made the game a lot more interesting. They were.
1. You can only have up to 12 infantry on one country.
2. The value of bonus cards start at 4 and thier value increases by 1 every time a set is turn in.
3. When attacking you can change 1 dice to 6 once per turn.
4. If you have a bonus card with the name of a country that you are attacking from or attacking you can reroll 1 dice every roll after revealing the card to everyone else.
Rule 3 is not very important, and rule 4 is not either allthough they both can make the game more strategic by giving everyone more motivation to attack before attacked. Rule 1 is a very useful rule that increases the value of countries that have less borders. Making continets such as North America, South America, and Oceanasia easier to defend. While at the same time making continets like Africa and Europe harder to take care of.