So my mental picture of Israel wandering in the wilderness for 40 years is something like spending your morning getting a jug of water and scraping manna off the desert floor and the afternoon trying to turn it into bread for dinner while trying not to get sunburned again.
Today we read of the deaths of Miriam and Aaron. Miriam is associated with the water supply. I have read some things online (its from the internet so it must be true) that suggest the Israelites actually had a loose boulder they carried with them from which Miriam would call water. Regardless, Miriam's death causes a water crisis and then Moses' fate is locked in when he doesn't follow the very specific instructions from God for getting water. Aaron is called home, literally. That must have been a very lonely time for Moses (now probably over 100 yrs old). Fortunately, he had a few distractions to keep him busy with the snake infestation and a few battles. The snakes came from grumbling, a natural human tendency and a word which may perfectly describe our culture today. That still fits in my mental picture of desert survival. My question is when did they train for combat because they seem to be pretty good at it.
The first encounter is with Edom. That is the tribe from Esau, Jacob's (Israel's) brother. It seems very inhospitable of the Edomites to not let Israel pass through, but in their defense this is a parade of about 2 million people. There would undoubtedly be the consumption of a lot of limited resources with a group that size and probably some property damage. The Israelites move on.
The first battle is with Arad, a southern most group of Canaanites who attacked first. The Israelites make an interesting vow to the Lord that if He will grant them victory, they will entirely destroy the cities of Arad. I think this means they promised not to loot the Canaanites. God gave victory. The Canaanites of Arad and their cities are entirely destroyed. Clearly the Canaanites are on God's "naughty list."
Next encounter is on the boarder of Moab (the tribe from Lot's son by his oldest daughter) with the Amorites. The Amorites were a tribe from Canaan (Gen 10:16) and were specifically called out by God in His covenant with Abraham in Gen 15:16, "...for the iniquity of the Amorites is not yet complete"
Israel fought two Amorite kings: Sihon and Og. Og was an infamous Rephaite (giant). The cities won in these battles will later be occupied by some of the Israelites. More battles with other Amorites will come on the other side of the Jordan. There is no real desription of the battles, but in the tradition of ancient combat we can expect at least all the men of fighting age and possibly all people were killed. The Amorites have been on God's list for quite a while. This seems harsh, but the depravity and disrespect of this idolatrous group must have been overwhelming.