More than 1,500 Columbia alumni are threatening to withhold donations from their alma mater until it agrees to divest from Israel, remove the New York Police Department from the campus and drop charges against the pro-Palestinian student activists, among other demands - in a boycott that could cost the university more than $63 million.

The letter, which claims to represent more than 20 organizations, including various affinity groups and schools within Columbia, was initially sent to university President Minouche Shafik on May 3. The signatories expressed "firm and unwavering solidarity with all students, staff, and Columbia community members taking principled action to stop the University's continued collaboration with the Israeli government's ongoing genocidal violence against Palestinians."

"Peaceful escalation is a longstanding part of Columbia's legacy of student activism-a legacy which Columbia itself often uses to recruit prospective students," the letter reads. "We urge Columbia to learn from its own history - failures and successes alike - and follow the lead of its student activists at this pivotal moment."

Columbia University attracted international attention - and scrutiny - after Shafik twice authorized the NYPD to enter the campus and arrest protestors who occupied a campus lawn and then an academic building. Following the students' occupation of Hamilton Hall, she also requested that the police remain on campus until May 17, two days after commencement.

The letters' signatories condemned the university's decision to allow the NYPD on campus while barring the press and legal observers from monitoring the situation.

"We have seen reports that students were subject to military tactics, including the use of stun grenades, flash bangs, and gunfire," the letter reads.

"That police severely injured multiple students; that many were denied access to medication, food, and water once in police custody; that police forcibly removed Muslim students' hijabs in the presence of men, an unforgivable violation of their religious rights; and other alarming instances of mistreatment."

The letter's Jewish signatories also criticized the university for "weaponizing claims about antisemitism" - arguing that in doing so the university was endangering its Jewish students, many of whom are involved in pro-Palestinian activism. They also called on Columbia to reinstate Jewish Voice for Peace - a pro-Palestinian Jewish group that was barred from campus in the aftermath of the October 7 Hamas attacks in Israel.

The letter concluded by calling attention to the Palestinians sheltering in Rafah, who are facing unprecedented Israeli bombardment, in one of the last remaining habitable areas of the Gaza Strip.

"The University must now act boldly in support of Palestinian life and liberation," the alumni wrote. Anything less is a betrayal of the core lessons we were taught at Columbia University."