In Gaza, the bad blood has some history. During the 2008-2009 Gaza incursion, UNRWA reported that Israeli strikes damaged dozens of its facilities. In one strike, Israeli shells set fire to a U.N. warehouse, and Israel eventually paid compensation. For its part, Israel has accused the United Nations of specific misconduct, including transporting Hamas rockets in a U.N. ambulance — a charge Israeli officials later retracted. The broader Israeli critique is that UNRWA nurses Palestinian grievances and has acquiesced to the militarization of the territory by extremists such as Hamas. In 2002, a spokesman for then-Prime Minister Ariel Sharon called for an investigation of what he described as “30 years of abuse of refugee camps by the Palestinians” and the United Nations’ “bond of silence” toward it.

Animated by similar concerns, the U.S. government has conducted investigations of UNRWA’s operations on its own, and Canada recently redirected some of its funding from UNRWA to other channels. The discovery of Hamas rockets in several UNRWA schools during the current conflict — quickly condemned by U.N. officials — has only deepened the suspicions of Israel’s supporters that UNRWA is, in effect, aligned with Hamas.

The controversy surrounding the United Nations is particularly intense in Gaza but not unique to it. In some conflict zones, the United Nations has come to be seen as a proxy for one side or as the embodiment of an international policy that certain combatants reject. In these cases, the organization serves as a tempting target for extremists looking to make a point and generate headlines. Two U.N. aid workers were shot and killed in Somalia in late 2011. Earlier that year, Boko Haram militants detonated a bomb outside a U.N. building in Abuja, Nigeria, killing 21. In 2009, Taliban operatives killed five U.N. workers in Afghanistan. And most notorious, Iraqi insurgents bombed the U.N. compound in Baghdad in August 2003, an attack that claimed the lives of top official Sergio Vieira de Mello and more than a dozen others.