sharu3

You have to make an alliance with any nation and when they need help the help ally option will come up,when they are attacking a nation the joint attack option will come up,and to answer your question,you will need to make an alliance with someone and when a policy comes up that says something about your ally(on the bottom it will say renforcements or something like that.)

Tip:to every one who plays the game,when your nation is under attack and youwant to take over something bad,just let it be under attack and it wiil still be there,but if they attack it again,it will be lost.Another tip is that if a nation is attacking you and there leader is not attacking you,attack there leader(if you can)and you will take over all there land and there invasion will be repeled.