I doubt they want to expand in Pakistan, not much they can do here not enough shia Muslim's for them too expand.In order for us to understand post 1979 Iran one has to study and understand the foreign policy objectives of the regime. In Khomeini's own words: We shall export our revolution to the whole world. The fatwa given by that person ordered his regime to the spread of his revolution over state-to-state, which essentially means expansionism. Now how you achieve that expansionism? By creating proxies..... the assassins', the mercenaries whose only job is to kill to achieve their objective.
Now have a cursory look on the world map. Iran’s Revolutionary Guards and the elite Qods Force has been providing arms, training and financial support to militias and terror proxies in at least six countries: Bahrain, Iraq, Lebanon, the Palestinian Territories, Syria and Yemen. There are almost a dozen terrorist groups financed by Iran in Pakistan.
My dear I don't talk in the air, I have researched a lot on this subject.
They have influence in Iraq due too lot of shia people living there.