Contrary to popular singers, Achdus has only instrumental value. That is the difference between the future unity described in the Prophets, in order to serve God, and the undiscriminating ecumenicity of the Tower of Babel, (not to mention unity is only possible in the long term for a transcendental value).
For more as this applies to the “United Nations” abomination, see “THE PROBLEM OF NATIONALISM” – A dialogue with Stuart Hampshire, chaired by Bryan Magee.