Who is the northwestern  neighbor of the country that boarders Iran on the northeast?
Turkmenistan Turkmenistan ( or ; Turkmen: Türkmenistan/Түркменистан/توركمنستان , ), formerly known as Turkmenia, is a country in Central Asia, bordered by Kazakhstan to the northwest, Uzbekistan to the north and east, Afghanistan to the southeast, Iran to the south and southwest, and the Caspian Sea to the west.
Eastern Iran Eastern Iran includes the provinces North Khorasan, Razavi Khorasan, South Khorasan and Sistan and Baluchestan some of which share a border with Afghanistan and Pakistan. Some references also count Kerman Province to this region.