The 1960s war in Yemen also saw some action by Pakistan and Wiki says that "Pakistan saw an opportunity to make money and supplied rifles". That Paki approach to smell money from far away remains for ever etched in stone !
KSA is facing multiple threats and that was why the King and his entire cabinet was at the King's terminus in Riyadh to receive Nawaz Sharif when he went there last week. I have not heard of even visiting Kings from neighbouring GCC or the President of the US being accorded such a welcome. Besides, this fabulous reception could not have been because of Nawaz's connection with the Saudi royalty. Of course Nawaz had contacts with the Royalty such as King Fahd (dead), Prince Sultan (then defence minister since dead and who was largely instrumental in the nuclear deal) or King Abdullah (dead). Prince Salman was simply the Governor of Riyadh who was not involved in international affairs like the above three. Hence, this reception is more institutionalized and reflects the desperation of the entire government.
KSA's entanglement in the Levant went awfully wrong and will certainly backfire as it did with OBL. KSA feels threatened by the approaching denouement in the Iran nuclear issue. There is significant Shi'a population on the oil-bearing east from Kuwait all the way to Bahrain, along the Persian Gulf. The Bahrain situation is bad and can erupt anytime. The dominant Saudi Shi'a population from the critical Al-Jubail area near the Kuwait border up to Dhahran near Bahrain have been restive for a long time. The Yemeni revolt by the Shi'a, the Saudi support against them in the Levant and Yemen, can cause problems. The Saudi economy is hit hard by the oil prices and nobody would know how far the Sunni extremism and anti-monarchy feelings would flare up when KSA falls into hard times. Sensing Saudi weakness, Pakistan would demand its pound of flesh now. Already, a Apkistani federal minister accused Saudi Arabia directly of being the cause of problems in the Pakistani society and the Saudis meekly took it.
The Iranians are certainly trying to relieve the pressure by creating a new front. Will the IS move some of their forces there, or the 10-party coalition collude with the IS in Yemen or enter into a secret deal with AQIP instead?
All in all, more interesting time to keep a close watch on.