The informant is a nineteen-year old student born in Australia whos lived in Egypt for two years, England for two years, Jordan for four years, Egypt for two years, India for four years and currently resides in Los Angeles, CA for university. He is the son of an Egyptian ambassador and speaks Arabic, English and French. He shall be referred to as SH.
If you have a lot of enemies, you probably have a very high fence.
SH explains that this is used alternatively with the reflexive version (If you have a high fence, you probably have a lot of enemies). He further elaborates that it is usually told in the context of leaders (either to a leader, from a leader, or between leaders) in regards to justness. He explains how someone who is just has no reason to fear anyone, and thus should not worry about retribution from anyone. However, someone who is very defensive is likely to have wronged someone.
I thought that as the relative of an important figure, SH would likely have come across this proverb in that context. Upon further analysis, this proverb suggests that injustice will always receive retribution. As this is a common phrase in a Muslim area, there is a belief in a higher power that will doll out justice for someone who has been wronged. This seems to be an understanding on a mortal level as well; someone who has a lot of enemies does not expect to get away with their crime, but instead chooses to build a tall fence to protect him or herself. Thus, even those who commit injustice expect it to be returned to them in this society.