Immediately following its birth as an independent nation, Pakistan also has to establish its legitimacy against a possible challenge from Afghanistan.

Irredentist claims from Kabul are based on the ethnic unity of tribes straddling the border; the emotional appeal of "Pakhtunistan," homeland of the Pakhtuns, or Pashtuns, is undeniable.

However, Pakistan upholds the treaties Britain had signed with Afghanistan and refuses to discuss the validity of the Durand Line as the international border.

Relations with Afghanistan are hostile, resulting in the rupture of diplomatic and commercial relations and leading Afghanistan to cast the only vote against Pakistan's admission to the United Nations in 1947.