Here's my suggestion... I kinda instinctively expected it to happen but when it didn't realized that I should propose it..
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Let's say I'm attacking an Enemy(E) together with my Allies(A) and one of my A's captures the E's capital.
Currently only the person who captured the capital gets a Morale boost.
I believe that the boost should be experienced by all the Allies that were at war with that Enemy.
Historic example: when Berlin was captured by Russians, America and other allies declared victory in Europe and celebrated.
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Let's say I'm attacking an Enemy(E) together with my Allies(A) and one of my A's captures the E's capital.
Currently only the person who captured the capital gets a Morale boost.
I believe that the boost should be experienced by all the Allies that were at war with that Enemy.
Historic example: when Berlin was captured by Russians, America and other allies declared victory in Europe and celebrated.