I need to research this farther. But what if the Syrian coup of 1961 had failed? The observation that the coup had some popular support may have motivated Nasser to allow more autonomy to the Syrians within the United Arab Republic. Iraq, already in the process of joining the UAR, would have become part of the federation on schedule within a year or so. Yemen (Sana'a) may have also drawn closer to the UAR.
So, assuming the federation can hold together, we end up with a very large power covering much of the Arab world, one that is as opposed to Jordan as it is to Israel. The Six Day War is butterflied away, but some united action against Israel seems in the cards.
So do we have SecularArabWank - or an even more endless and irretractable conflict?