All would suffer in the late Bronze Age (LBA) collapse, with the Hittite empire collapsing soon after a string of three drought years about half a century after the treaty. Egypt and Assyria, at least, would persist in truncated form, with the latter rising to new heights of power in the Iron Age.

Wonder how long it lasted?

Edit: turns out it lasted until the Hittite empire collapsed 80 years later, so in a sense indeed "forever".

https://www.youtube.com/watch?v=3MZq_ZQDhJA

It reads more like a military alliance agreement between kings:

1. Reamasesa-Mai-amana (King of Egypt) and Hattusili (King of Hatti) are best friends forever.

2. If a foreign country invaded one of us, the other one must send his troops.

3. Ditto with civil wars. We help each other.

4. If a high-profile person flees from Egypt or Hatti, send the bastard back.

5. If people flee from Hatti to Egypt, order them back. Do not retaliate against returnees, though. No pulling eyes/tongues. No cutting feet/ears. No destroying wives/houses/kids. Please.