In theory any country that Microsoft and/or Activision do business in could make a point to approve or disapprove the acquisition.
The repercussions of that are going to depend on the enforcement mechanism, but in practice I’d expect in most cases it’d work out to being barred from doing business there either de jure or de facto (fined to the point of making it pointless). Large countries will have enough power that major corporations would be obligated to accept a negative decision. Medium countries could possibly leverage a negative decision into a desirable concession. Small countries have no leverage and will be aware of that.
In theory any country that Microsoft and/or Activision do business in could make a point to approve or disapprove the acquisition.
The repercussions of that are going to depend on the enforcement mechanism, but in practice I’d expect in most cases it’d work out to being barred from doing business there either de jure or de facto (fined to the point of making it pointless). Large countries will have enough power that major corporations would be obligated to accept a negative decision. Medium countries could possibly leverage a negative decision into a desirable concession. Small countries have no leverage and will be aware of that.