It has been striking in the past week to watch the shift of opinion among top UN officials, including Secretary-General Ban Ki-Moon, as they have observed the toll of Israeli attacks on Gaza’s population.

In contrast to the refusal of the US to blame Israel’s Government and military for the civilian deaths, the UN officials have moved to sharp criticism of West Jerusalem amid the deadly airstrikes and shelling, including on shelters for Gaza’s displaced people.

And this is not a calculated political response — it is an emotive reaction to the devastation and mass killing.

Chris Gunness the spokesman for the UN refugee agency UNRWA, broke down on Wednesday as he was interviewed by Al Jazeera Arabic about an attack on a UN shelter in Jabaliya that killed at least 19 people and wounded more than 90: