Sikh children displaced from their homeland in Bruner, North West Frontier, Pakistan being fed at Gurdwara Panja Sahib, Pakistan. This displacement is due to the Taliban and it’s ideology of religious extremism.
Sikhs of course have a legal right under International Law to claim territories in Pakistan. The legal basis of this claim is that under the English Common Law pertaining to colonies, the law provided that the colonies had to be handed over to the Rulers and Nobility from whom it was conquered. This was well established common law. Thus all the rulers of the erstwhile princely states in India had to sign an instrument of acession to either Pakistan or India. Thus for example, the Hindu Ruler of Kashmir executed an instrument of accession to India. No Sikh ever signed an instrument of accession to Pakistan or India because the sticking issue was the theo-political status of Sikhs. The last sovereign in the line of Maharajah Ranjit Singh was an Englishman (the grandson of Maharajah Duleep Singh) and he never signed any instrument of accession.
Sikhs wanted accession to India under a status similar to Bhutan and Sikkim. The Congress party refused to accede to this demand but agreed to constitute a Sikkim and Bhutan like status for the Sikhs under an Act Of Parliament. An Act of Parliament (Lok Sabha) was passed which created PEPSU (The Punjab East States Union). But this Act was rescinded in 1955 under the manufactured pretense of the Malerkotla Rape Case. In the Malerkotla Rape Case, a person who had allegedly raped a girl in Malerkotla fled to PEPSU; the Indian police was in hot pursuit. The PEPSU police rightfully (under the laws of PEPSU) prevented the Indian police party from crossing the border since policing was an internal PEPSU matter and under it’s sole jurisdiction. This false flag operation triggered the dissolution of PEPSU by a Parliament dominated by Hindus. The PEPSU issue is moot now.
In the context of Pakistan which is a failed state and ready to completely disintegrate, if the Sikhs were an astute, brave and an educated people (they are not) they would raise the accession issue and demand sovereignity rights in the rapidly dissolving failed state of Pakistan. They have a legal basis for their claim and there is a lot of land in Pakistan for Sikh settlement.