This week in Pittsburgh, the General Assembly of the Presbyterian Church will vote on a measure to divest from three companies with extensive links to Israel’s occupation of Palestinian territory: Caterpillar, which makes the armed bulldozers used to destroy Palestinian homes, and Motorola Solutions and Hewlett Packard, which sell Israel measures to help supervise and control the Palestinian population it rules over.

This proposal has been working its way through the Presbyterian political structure for a decade, after it became the clear that the Oslo peace process had failed. I doubt anyone believes divestment from three companies will have much economic impact on Israel, or the selected companies. But it will have major symbolic significance, which explains why various components of the Israel lobby have rolled out the heavy artillery to squelch the measure. Perhaps more than any other Protestant denomination the Presbyterians have a longstanding presence in the Arab world, as missionaries, as healers of the sick, as educators. Yet while they have spoken out from the outset for the Palestinian refugees their voice was often timid and muted by desire to avoid open disagreement with the assertive and increasingly right-wing voices of established Jewish organizations.

It is now clear that a fair number of Presbyterians have decided that — forced to choose between keeping silent about injustice and giving offense to their Jewish religious partners — muting their beliefs about the occupation is no longer an option. On the eve of the conference, the Pittsburgh Tribune-Review published Dr. Leila Richard’s eloquent explanation why the divestment campaign is necessary. In a related development, a Christian group, the US Kairos Committee, has called on American Christians to not be silenced by fear of being labeled anti-Semites by Israel’s supporters. The group reminded Christians that “The tragic realities of Israel and Palestine today would deeply trouble Jesus and the prophets … Palestinians are prisoners in their own land, powerless as Israel’s program of dispossession and annexation continues.”

The larger issue here is whether American Christians are awakening to the fact that they — as citizens — have strategic and moral interests in the Middle East that do not coincide with unconditional diplomatic and financial support for Israel. For two generations now, the mainline Protestant churches, and the broader Protestant establishment to which they are connected, have been unfailingly deferential before the claims of Israel’s supporters. Such patterns of deference won’t end in a week, or a year. But the assembly this week in Pittsburgh could well signal the beginning of the end.