During the Shah era, when Bhutto was in power in Pakistan, Pakistan requested Iran’s help in counter insurgency operations against Baloch insurgents in Balochistan. Iran provided aircover through their cobra gunships (Pak didn’t possess cobras at the time) while Pak Army troops carried out the operation on ground. Hopefully once the defence related international sanctions are removed, Pakistan and Iran can collaborate more in a similar fashion against a foreign sponsored common threat in Pak-Iran border region. With Iran joining SCO, the defence collaboration would increase tenfold, as Pakistan is also a member of that security organization.