A coalition of unions representing nearly half of all union members in the United States sent a letter this week urging President Joe Biden to halt all US military aid to Israel. The letter, sent ahead of Israeli prime minister Benjamin Netanyahu’s visit to the US today, urges Biden to stop arming Israel “as part of the work to secure an immediate and permanent cease-fire in the war in Gaza.”

Seven unions signed onto the missive: the Association of Flight Attendants–Communications Workers of America (AFA-CWA), the American Postal Workers Union (APWU), the International Union of Painters and Allied Trades (IUPAT), the National Education Association (NEA), the Service Employees International Union (SEIU), the United Auto Workers (UAW), and the United Electrical, Radio and Machine Workers (UE). Taken together, the signatories comprise some six million workers.

“Our unions are hearing the cries of humanity as this vicious war continues,” said APWU president Mark Dimondstein in a press release. “Working people and our unions are horrified that our tax dollars are financing this ongoing tragedy. We need a ceasefire now, and the best way to secure that is to shut off US military aid to Israel.”

Dimondstein was the first leader within the AFL-CIO to begin pushing unions to endorse a cease-fire. He raised the issue at an October 16 meeting of the AFL-CIO executive council, urging the body to demand a cease-fire. According to the New York Times’s reporting, he found no support among his colleagues — the AFL-CIO has previously quashed efforts to back such a call at the local level. But to have criticism of Israel raised at length in such a meeting was itself unprecedented.

This week’s letter to Biden is a product of relationships built through the National Labor Network for Ceasefire, a coalition of unions that formed around a statement, initially sponsored by UE and United Food and Commercial Workers International Union (UFCW) Local 3000. That statement called on Biden and Congress to “push for an immediate ceasefire and end to the siege of Gaza,” stopping short of calling for an end to US military aid to Israel.

UE has long supported such a demand, codifying it in a resolution passed at their national convention last September. The independent union has long occupied the left wing of the US labor movement — so much so that they faced merciless red-baiting during the McCarthyist era, and expulsion from the Congress of Industrial Organizations (CIO), decimating their membership at the time. But bringing along other unions took time, and according to sources familiar with the negotiations, this week’s letter was the product of months of conversations and organizing.

SEIU and the NEA for instance, are not often grouped with the likes of UE and the UAW, the latter of which, under the new reform leadership of President Shawn Fain, has become more outspoken on foreign policy, calling for a permanent cease-fire in December 2023 and building ties with independent autoworkers’ unions in Mexico. SEIU and NEA first needed to raise the matter at their respective conventions before signing on to this week’s letter.

Those gatherings were held in May and early July, with both unions discussing resolutions calling for an end to US military aid to a country that has killed upward of forty thousand Palestinians in the past year (and likely far more, as Israel’s targeting of the Gaza Strip’s civilian infrastructure has ground the tallying of deaths to a halt.)

This letter follows a webinar the National Labor Network for Ceasefire hosted earlier this month, which was emceed by Dimondstein and featured representatives of the Palestinian Journalists’ Syndicate, the General Union of Transport and Communications Workers, and the General Union of Health Services Workers in Gaza. According to people familiar with the network’s internal organizing, that event was preceded by an off-the-record preparatory meeting between the US union leaders and their Palestinian counterparts. Palestinian trade-union leaders have long called for union leaders to push for an end to the US government arming Israel.

“Recent reports only underscore the urgency of our demands,” the letter continues. “Large numbers of Palestinian civilians, many of them children, continue to be killed, reportedly often with US-manufactured bombs. Rising tensions in the region threaten to ensnare even more innocent civilians in a wider war. And the humanitarian crisis deepens by the day, with famine, mass displacement, and destruction of basic infrastructure including schools and hospitals. We have spoken directly to leaders of Palestinian trade unions who told us heart-wrenching stories of the conditions faced by working people in Gaza.”

Biden has ended his reelection bid, but he intends to remain the country’s president for the duration of the year. There is no telling how many Palestinians Israel will kill in that interim, and as Kamala Harris seeks the votes of the millions of workers who are members of the signatory unions. In releasing this week’s letter, union leaders and the members who have pushed them on the issue hope to demonstrate the centrality of the issue to both Biden and Harris, at last acting in keeping with the wishes of the Palestinian trade-union movement’s demand for solidarity.