Pakistan and Iran have close cultural, religious, and economic ties dating back centuries. They share a 909 km border and have supported each other militarily and politically, including during the 1965 and 1971 Indo-Pakistani wars where Iran provided military aid to Pakistan. Economic cooperation has increased in recent decades through agreements like the Iran-Pakistan gas pipeline and preferential trade deals, though American opposition to Iran poses challenges. Defense cooperation is also an important aspect of the bilateral relationship.