Postive effects could be that it brings people together, gives them a community for supporting each other, focuses their attention on God. It provides a moral framework, comfort for those in need, the promise of an afterlife... and so on.
Negative effects are that the different religions can be seen to inspire conflict in the world, some might say that they focus people too much on religious things rather than on day to day things (so you lose the plot basically!).
There was abundant evidence that Americans of Japanese descent were engaged in a widespread campaign of domestic spying, subversion, and sabotage on behalf of Japan.
