The defeated union of kingdoms did not send a clear message to the other cities in the area.  There seems to be a condition that hardens the heart and minds of the unrepentant.  Sin can neutralize common sense.

And it came to pass, when Jabin king of Hazor had heard those things, that he sent to Jobab king of Madon, and to the king of Shimron, and to the king of Achshaph,  And to the kings that were on the north of the mountains, and of the plains south of Chinneroth, and in the valley, and in the borders of Dor on the west,  And to the Canaanite on the east and on the west, and to the Amorite, and the Hittite, and the Perizzite, and the Jebusite in the mountains, and to the Hivite under Hermon in the land of Mizpeh.  And they went out, they and all their hosts with them, much people, even as the sand that is upon the sea shore in multitude, with horses and chariots very many.  And when all these kings were met together, they came and pitched together at the waters of Merom, to fight against Israel.  Joshua 11:1-5

Again the cities try to unite against God.  The Lord himself speaks encouragement to Israel.

And the LORD said unto Joshua, Be not afraid because of them: for to morrow about this time will I deliver them up all slain before Israel: thou shalt hough their horses, and burn their chariots with fire.  So Joshua came, and all the people of war with him, against them by the waters of Merom suddenly; and they fell upon them.  And the LORD delivered them into the hand of Israel, who smote them, and chased them unto great Zidon, and unto Misrephothmaim, and unto the valley of Mizpeh eastward; and they smote them, until they left them none remaining.  And Joshua did unto them as the LORD bade him: he houghed their horses, and burnt their chariots with fire.  Joshua 11:6-9

God delivered his enemies into the hands of the armies of Israel.  They obey God by destroying all the inhabitants again. 

And Joshua at that time turned back, and took Hazor, and smote the king thereof with the sword: for Hazor beforetime was the head of all those kingdoms.  And they smote all the souls that were therein with the edge of the sword, utterly destroying them: there was not any left to breathe: and he burnt Hazor with fire.  And all the cities of those kings, and all the kings of them, did Joshua take, and smote them with the edge of the sword, and he utterly destroyed them, as Moses the servant of the LORD commanded.  But as for the cities that stood still in their strength, Israel burned none of them, save Hazor only; that did Joshua burn.  Joshua 11:10-13

This is so politically incorrect; to slaughter men women and children.  But then God does show favoritism.  We are no longer required to execute sinners, as they have grace if they repent.  We need to remember that we were the sinners destined for death before Yeshua Messiah.  We were the nations not born to Abraham, not his chosen people.  We have been received into fellowship by God’s kindness.    

And all the spoil of these cities, and the cattle, the children of Israel took for a prey unto themselves; but every man they smote with the edge of the sword, until they had destroyed them, neither left they any to breathe.  As the LORD commanded Moses his servant, so did Moses command Joshua, and so did Joshua; he left nothing undone of all that the LORD commanded Moses.  So Joshua took all that land, the hills, and all the south country, and all the land of Goshen, and the valley, and the plain, and the mountain of Israel, and the valley of the same;  Even from the mount Halak, that goeth up to Seir, even unto Baalgad in the valley of Lebanon under mount Hermon: and all their kings he took, and smote them, and slew them.  Joshua made war a long time with all those kings.  Joshua 11:14-18

How rare was Rahab the harlot, to escape the fate of all these nations.  How much more rare is her heritage to mother the children who led to the savior himself.  Christians are rare, compared to the vast numbers who die in their sins.  Few will find the great gift we have received in Christ.

There was not a city that made peace with the children of Israel, save the Hivites the inhabitants of Gibeon: all other they took in battle.  For it was of the LORD to harden their hearts, that they should come against Israel in battle, that he might destroy them utterly, and that they might have no favour, but that he might destroy them, as the LORD commanded Moses.  And at that time came Joshua, and cut off the Anakims from the mountains, from Hebron, from Debir, from Anab, and from all the mountains of Judah, and from all the mountains of Israel: Joshua destroyed them utterly with their cities.  There was none of the Anakims left in the land of the children of Israel: only in Gaza, in Gath, and in Ashdod, there remained.  So Joshua took the whole land, according to all that the LORD said unto Moses; and Joshua gave it for an inheritance unto Israel according to their divisions by their tribes. And the land rested from war.  Joshua 11:19-23

Now we, like Rahab and Ruth are joined to Israel to enjoy the inheritance of the Promised Land.  We have escaped the fate of these rebellious kingdoms, and we have inherited their place in eternity.  We are full partners in the family business, not slaves or bodies destroyed on the battlefield.  The majority of mankind misses this salvation, in spite of their fame, wealth, or power in this life.

Now these are the kings of the land, which the children of Israel smote, and possessed their land on the other side Jordan toward the rising of the sun, from the river Arnon unto mount Hermon, and all the plain on the east:  Sihon king of the Amorites, who dwelt in Heshbon, and ruled from Aroer, which is upon the bank of the river Arnon, and from the middle of the river, and from half Gilead, even unto the river Jabbok, which is the border of the children of Ammon;  And from the plain to the sea of Chinneroth on the east, and unto the sea of the plain, even the salt sea on the east, the way to Bethjeshimoth; and from the south, under Ashdothpisgah:  And the coast of Og king of Bashan, which was of the remnant of the giants, that dwelt at Ashtaroth and at Edrei,  And reigned in mount Hermon, and in Salcah, and in all Bashan, unto the border of the Geshurites and the Maachathites, and half Gilead, the border of Sihon king of Heshbon.  Them did Moses the servant of the LORD and the children of Israel smite: and Moses the servant of the LORD gave it for a possession unto the Reubenites, and the Gadites, and the half tribe of Manasseh.  Joshua 12:1-6

The Kings of Canaan are all history now.  In time the Babylonians, Persians and Romans would disperse Israel and allow others to occupy Palestine.  But even that name evokes the memory of the Philistines, who would linger stubbornly in the land to this day.

And these are the kings of the country which Joshua and the children of Israel smote on this side Jordan on the west, from Baalgad in the valley of Lebanon even unto the mount Halak, that goeth up to Seir; which Joshua gave unto the tribes of Israel for a possession according to their divisions;  In the mountains, and in the valleys, and in the plains, and in the springs, and in the wilderness, and in the south country; the Hittites, the Amorites, and the Canaanites, the Perizzites, the Hivites, and the Jebusites:  The king of Jericho, one; the king of Ai, which is beside Bethel, one;  The king of Jerusalem, one; the king of Hebron, one; 

The king of Jarmuth, one; the king of Lachish, one;

The king of Eglon, one; the king of Gezer, one;

The king of Debir, one; the king of Geder, one;

The king of Hormah, one; the king of Arad, one;

The king of Libnah, one; the king of Adullam, one;

The king of Makkedah, one; the king of Bethel, one;

The king of Tappuah, one; the king of Hepher, one;

The king of Aphek, one; the king of Lasharon, one;

The king of Madon, one; the king of Hazor, one;

The king of Shimronmeron, one; the king of Achshaph, one;

The king of Taanach, one; the king of Megiddo, one;

The king of Kedesh, one; the king of Jokneam of Carmel, one;

The king of Dor in the coast of Dor, one; the king of the nations of Gilgal, one;

The king of Tirzah, one: all the kings thirty and one.

Joshua 12:7-24

The slaughter of so many nations will not lock gentiles out of the Kingdom of God.  Remember that these nations, like the world of Noah, were condemned by God for their sin.  Today we can remember to resist the satanic spirits without mercy while allowing mercy to men.  We do not war against the flesh, but we do not tolerate the evil spirits that mislead them.   

How many more lost sheep will be grafted in from the gentile nations?  When will God gather the lost children of Abraham back to Yeshua their Messiah?  Tomorrow in Jerusalem?