Aid Card
An "Aid Card" could function identically to a "reverse" Sanctions Card, in that it multiplies income rather than divides it.
The reason for having it as a separate card however, would be so that one can have both sanctions and "reverse sanctions" in the same game. Additionally, it could be given unique functionality in that one can only use it on others. (Being able to use it on oneself could also be toggle-able like so many other features).
I think a card like this would have enormous appeal in 'Diplomacy' games, where a player might want to help an ally without directly involving themselves in combat. Particularly if other players' card use is kept secret.
A "duplicate" card type like this should be relatively easy to implement, and there's certainly precedent for it.
There’s no point to have a new card that adds armies when a negative sanctions card could be used.