Nasser was their original sponsor, the fedayeen emerged from there, but the Saudis took over the account in short order, although the GRU's Sakharovsky, chipped in with Fatah's financing, Later on, under General Simenov, the Cuban DGI provided training camps, and of course
the govts of Lebanon and Tunisia respectfully provided sanctuary

It's not apocalyptic, it's just mismanagement and subsequent blame shifting,by the part of the Hashemites, since King Saud evicted them from the Keeper of the Shrines, and seat of authority in Arabia