The IRA has disarmed..why not Hamas and others?

I think it's great news that the IRA has disarmed...but why not terrorist groups like Hamas, Islamic Jihad, etc???

The IRA has finally put its arsenal of weapons and explosives amassed during 35 years of the Troubles out of action, the head of the international arms decommissioning body said yesterday.

Gen John de Chastelain said he believed that the IRA had disposed of all its arms but questions were raised over the verification procedure when he said that his assertion would have to be taken on trust.

Unionists in Northern Ireland demanded disarmament before further political progress - why doesn't the International Community say the same about Palestinian terrorists?