What would you do if your citizenship were rejected once your passport expired?

Impossible, you would think - a travel document isn't your only, or even your primary, tie to your land of origin. But that was the fate of 140,000 Palestinians, as the Israeli newspaper Ha'aretz reported this week, when Israel quietly cancelled their West Bank residency status between 1967 and 1994. It was as if residents simply blinked out of existence when their travel documents expired.

This kind of immigration policy is not unheard of in other countries - many reserve the right to revoke the residency of a foreign national who has lived abroad for too long. But the West Bank is not a foreign country for Palestinians, nor should they be categorised as immigrants in their own land by an Israeli occupier.

And yet, such is the state of affairs west of the Jordan River, where dwindling water resources, land scarcity and soaring population growth have made the possibility of a viable Palestinian state seem more remote with each passing year.

For decades, Israel has pushed into Jerusalem and the West Bank without regard for international law. Western powers have turned a blind eye; the Palestinians' allies have objected with little effect.

But there is now a chance to close the door on that era of encroachment - and the stark evidence of Israel's strategy to rob Palestinians even of residency should provide further weight against it in the international arena. In September, the UN General Assembly will vote on recognition of a Palestinian state, a vote that will undoubtedly favour the Palestinians.

More needs to be done. We wonder what kind of Palestinian state can emerge as this unceasing march on what remain of Palestinian lands continues. This is not only a matter for the more than 100 countries who will vote in favour of recognition, but also Israel's patrons in the United States and Europe who have lent it a cloak of legitimacy.

Saeb Erekat, the former chief negotiator for the Palestinian Authority whose own brother had his residency revoked by this unjust policy, has called it a war crime and a "systematic policy of displacement". Given Israel's systematic plan of illegal colonisation, carried out as much by the wheels of bureaucracy as by soldiers on the streets, the world should listen to Mr Erekat's assessment.