Learn English – Looking for equivalent of Indian saying ” Apne gali mein kutta bhi sher hota hey” which means Every dog in his own territory is/becomes a lion

I am looking for equivalent of Indian saying " Apne gali mein kutte bhi sher hota hey" which is "In their own lane ( or street or area) dogs also are lions". the meaning is when the territory/terrain (or may apply to "circumstance") is favorable any dog (underdog) can become a king-of-its-jungle (as a leader).

Hypothetical Example: In a battle between American Army and say Thailand or Vietnam Army on the latter's land, American will have to accept defeat because _____________________ (Every dog in his territory is/becomes a lion)

Best Answer

The closest I can come up with is:

A man's home is his castle.

Aka "An Englishman's home is his castle."

From wiktionary:

proverbial expression of personal privacy and security

Other similar definitions (cambridge):

used to say that English people believe that they should control what happens in their own homes, and that no one else should tell them what to do there

It has the same sentiment as your phrase about your home turf being somewhere safe where you are king (lion = king of the jungle; castle = home of a king). However it’s different in that a castle's walls should defend you, whereas the dog's lane has no walls and his territory won’t inherently defend him.