Upon the defeat of prince Aki-izzi's league of Semitic and Harri rebels, Shubbiluliuma next turned his conquest toward central Syria, occupied and controlled by the Amorites. Much like northern Syria had Aleppo as its crown jewel, central Syria bore Kadesh, the most prestigious power center of the region, and the Hattic king reasoned that should it fall, the surrounding areas would be quick to follow. A theory that proved correct.
With the success of his Campaign of Syria thus far and central Syria fallen, Shubbiluliuma knew that there were greater riches extending beyond Syria, whose resources were quite matched in wealth and would see grand results in the eventual trade from it that would follow the war. The most fertile lands that he eyed with a hunger, lay southward, the lands of Aziru (Lebanon) and Palestine, specifically.
Syria, Aziru, and Palestine are collectively known as the Fertile Crescent, an area desired throughout history by many competing powerful kingdoms.
According to the Amarna letters, Shubbiluliuma's forces overwhelmed and defeated the remaining Amorite regions of Syria with ease, but once it came time to annex Aziru, were met by a fiercely unexpected resistance. Be it city-street or countryside, the defenders, though few, simply would not surrender. Despite his heightened interest in conquering the former Egyptian-satellite nations, upon Aziru's eventual submission (and compliance to a heavy monthly tribute that would lessen over time), the Hattic king ended his conquest here.
In the aftermath of the Hittite Empire's violent expansion, two empires now encroached upon the other. Hatta and Egypt. This was a most sensitive political situation and the first instance in a span of many years when two superpowers of the Near East directly bordered the other in such a confrontational manner.
The Hattic king treated with the Egyptian Pharoah and the battlefield changed from a clash of swords to a conversational war of words. Perhaps heated at first, in the end, Shubbiluliuma and Amenhotep III signed a peace treaty. Hatta would retain control over Aziru whilst Egypt would retain control over Palestine, and neither empire would take arms against the other, as far as both monarchs ruled.
And while all agreements prove temporary over time, neither side challenged the limit of the treaty, with much to gain from mutual obeyance. The Hittite forces bore wartime exhaustion and the Egyptian empire was in a state of rapid decline which extended to the waning size and scope of their once mighty military. For a lengthy period, the security measures were respected by both nations, peace terms held intact.