The European Union expressed "grave concern" over the incident, with the bloc's foreign policy chief calling for immediate transparency in the U.S. investigation. France and Germany separately issued statements emphasizing the obligation of all parties to respect international humanitarian law.

The strike has complicated an already fraught diplomatic situation. Back-channel negotiations between Washington and Tehran, mediated by Qatar and Oman, had shown tentative signs of progress before this incident. Those talks have now collapsed, according to three diplomatic sources familiar with the discussions.

Within Iran, the tragedy has unified a population that had shown signs of division over the conflict. Mass demonstrations erupted across Iranian cities, with protesters carrying photographs of the victims and chanting anti-American slogans. The incident has also strengthened hardliners within the Iranian government who opposed any accommodation with Washington.

For the United States, the confirmation represents a significant blow to its claims of conducting a "precision campaign" against Iranian military targets. The incident has drawn comparisons to previous civilian casualty events in Iraq and Afghanistan that eroded international support for U.S. military operations.

Congressional leaders from both parties have called for hearings to examine the targeting procedures that led to the strike. Senator Jack Reed, chairman of the Armed Services Committee, announced plans for closed-door briefings next week to review the military's rules of engagement and oversight mechanisms.

The humanitarian implications extend beyond the immediate tragedy. The United Nations has warned that the school strike may deter families from keeping children in educational institutions, potentially affecting hundreds of thousands of students across conflict zones in Iran. Aid organizations report that civilian infrastructure including hospitals and schools has increasingly come under fire as the conflict intensifies.

As of Friday evening, the Pentagon had not released details about the specific circumstances that led to the school being targeted, citing the ongoing investigation. Military officials privately acknowledged that the incident would require a comprehensive review of intelligence gathering, target verification, and strike authorization procedures across the theater of operations.

The confirmed death toll of 150 includes children aged 6 to 12, along with teachers and staff members who were in the building at the time of the strike. Iranian authorities have said additional victims may remain buried in the rubble, suggesting the final casualty count could rise.