ISLAMABAD, Pakistan: Saudi Arabia and Pakistan have formalized a sweeping mutual defense pact that commits each to view any attack on the other as a direct assault on itself. For decades, Riyadh and Islamabad have maintained deep economic, religious, and military ties. That history has fueled speculation that Saudi Arabia could one day come under Pakistan's "nuclear umbrella," particularly as fears over Iran's nuclear ambitions intensified. Pakistani troops were first deployed to Saudi Arabia in the late 1960s amid fears of regional instability following Egypt's intervention in Yemen. Notably, just before the pact was announced, Iran dispatched senior official Ali Larijani to Riyadh.