In Animal Farm, what is the dispute about defense of the farm? Which one is no longer in effect on the farm?

Napoleon and Snowball disagree about the best way to defend the farm. Snowball wants to create more rebellions on other farms by sending the pigeons to stir things up. Napoleon thinks the best way to secure their safety is to do it from within. He wants to get weapons and train the animals to use them.

Snowball believes the way to improve the farm is through the building of a windmill. Napoleon does not think it is a good idea, he wants to increase food production. They decide to put it to a vote. When the animals come together to vote, and the vote appears to favor  Snowball's idea, Napoleon cues the nine dogs he took under his wing, and they rush at Snowball. Snowball is forced to run for his life, and narrowly escapes. He is never heard from again.