After Iraq, Pakistan. Did you know that it’s an acronym?

It was coined in 1933 as Pakstan by Choudhry Rahmat Ali, a Pakistan Movement activist, who published it in his pamphlet Now or Never, using it as an acronym (“thirty million Muslim brethren who live in PAKSTAN”) referring to the names of the five northern regions of the British Raj: Punjab, Afghania, Kashmir, Sindh, and Baluchistan”. The letter i was incorporated to ease pronunciation and form the linguistically correct and meaningful name: it literally means “Land of the Pure” in Urdu and Persian. It comes from the word pāk, meaning “pure” in Persian and Pashto, while the word istān is a Persian word meaning “place of”.

Wikipedia entry on the etymology of Pakistan