Let us take an introspective look upon when this troublesome mass migration from the westerners began, leading up to Egypt's successful battlefield engagements against them. The Pisidians who dwelt from Sagalassos along with the feather-crested battle-armored Lycians of Lycia and Carians of Caria (all geographically located throughout modern day Turkey) gathered and pushed southwestward.
According to Egyptian record, no land could stand against this massive horde, and upon their departure from Anatolia, one-by-one the Syrian city-states began to fall. There were two notable divisions amongst this threat to the Near East:
The shipmen and the land-horde.
First it was Alashiya that was attacked, overrun by shipmen who assaulted from the sea. Upon victory, the migrant fleet next completely overtook the Syrian Gulf of Issus, permanently circling its coastline in its callous occupation.
The land-horde however marched into Syria en masse. Arvad, Cappadocia, and of course the legendary historic city of Carchemish were not spared. These places of import, their beauty first desecrated, were largely destroyed by this land-horde, with many citizens likely losing their lives as foreign invasions of this nature rarely offer much in the ways of mercy.
The Amurru kingdom (Palestine) was next attacked and leveled, and it was here that the massive push was halted. We know what came next with the battles between Egypt and the Sea Peoples, but massive damage had been done to Egypt's subjects, and the Near East now bore a literal culture war on its hands between the native kingdoms and the invaders.
When you fear nothing, doubt is eliminated. If your enemies project weakness, then the time to attack is immediate. Thusly, the doubtless hordes of the west immediately attacked the Syrian princes, who'd in the past always relied upon the protections of either the Hittites or the Egyptians, themselves noticeably possessing no desire to fight. And it all fell apart. Trade was displaced and there was no preventing the trail that was blazed right through their land.
This is not to overshadow the achievements of Egypt in defeating the Sea Peoples when it eventually came to thwarting direct attack, but if one thing can be ascertained about Ancient Egypt it is that defending her subjects was not one of her strengths, if the Upper Levant region is any indication.
[THE FORTRESS OF ARVAD]