State Department officials have been collecting information on the incidents from media reports, civil society groups, and foreign government contacts since 7 October 2023.

The Post reported, citing anonymous sources, that some of the cases presented to the State Department over the past year likely constitute violations of US and international law.

Human rights advocates highlight that many incidents involve documented US-made bomb fragments found at sites where numerous civilians, including children, were killed.

Among the cases submitted to the State Department, according to people familiar with the matter, is the January killing of six-year-old Hind Rajab and her family in their car, with pieces of a US-made 120mm tank round purportedly found at the scene.

According to the Post, the State Department’s internal Civilian Harm Incident Response Guidance, designed to track the misuse of US-origin weapons, has failed to advance these cases to the “action” stage despite a requirement to act within two months. Consequently, over two-thirds of the cases remain unresolved, raising concerns about accountability.

Critics argue this inaction reflects the Biden administration's reluctance to hold Israel accountable amid its year-long war on Gaza, which has killed at least 43,000 people in the besieged territory.

In May, the US issued a rare criticism of Israel's use of American weapons in its war on Gaza after Israeli forces intensified attacks around the southern Gaza city of Rafah earlier that month.

Israel's main international ally had at the time said in a report that it was "reasonable to assess" that Israel has used weapons in instances “inconsistent” with its obligations under international humanitarian law “or with best practices for mitigating civilian harm” during its war on Gaza.

However, the long-awaited State Department report said it could not reach "conclusive findings" and stopped short of blocking weapons shipments. 

Previously, US President Joe Biden said he would halt some arms deliveries if Israel went ahead with a full-scale assault on Rafah. 

In March, the State Department received Israel’s required written assurances that its use of US-supplied defence equipment does not violate such laws. Accordingly, if Israel’s pledges were found wanting, Biden had the option at any point of suspending any further US arms transfers—something he has failed to do despite the mounting evidence against Israel.

However, senior US officials said they do not find "credible or reliable" Israel's assurances that its use of US-supplied weapons in Gaza adheres to international humanitarian law, according to an internal State Department memo seen by Reuters in April.

In the initial "options memo," submitted to US Secretary of State Antony Blinken, four State Department bureaus – Democracy, Human Rights, and Labor; Population, Refugees and Migration; Global Criminal Justice; and International Organization Affairs – raised "serious concern over non-compliance" with international humanitarian law during Israel's prosecution of the Gaza war.

The assessment from the four bureaus said Israel's assurances were "neither credible nor reliable," the news agency confirmed.

Human Rights Watch and Oxfam have called on the Biden administration to rule that any Israeli assurances are “not credible” and to impose the “immediate suspension” of arms transfers. They issued a joint report documenting what they said were clear “violations of international humanitarian law, deprivation of services critical to the survival of the civilian population, and arbitrary denial and restrictions of humanitarian aid.”

The UN Human Rights Council has also demanded a halt to all arms sales to Israel, calling for Israel to be held accountable for possible war crimes. UN experts warned that "any transfer of weapons or ammunition to Israel that would be used in Gaza is likely to violate international humanitarian law and must cease immediately."

Nearly $23 billion and counting

Israel is the largest cumulative recipient of US military aid since World War II, and the Biden administration has provided it with at least $17.9 billion in military assistance in the past year alone, according to a recent study by Brown University’s Watson Institute for International and Public Affairs.

Despite the US being aware that these weapons are used against civilians, nearly all military assistance, apart from a delayed shipment of 2,000-pound bombs, has continued to flow without interruption, the Post reported.

“The US is the biggest donor to Israel with these weapons,” said Sarah Yager, the Washington director at Human Rights Watch. “And it’s a year in. When is the United States going to put its foot down?”

In August, US Secretary of State Antony Blinken approved the sale to Israel of F-15 jets and equipment worth nearly $19 billion along with tank cartridges valued at $774 million, explosive mortar cartridges valued at over $60 million and army vehicles worth $583 million, the Pentagon said in a statement.

US spending on Israel’s military operations and related US operations in the region total at least $22.76 billion and counting, Watson Institute for International and Public Affairs said in its most recent report.

"This estimate is conservative; while it includes approved security assistance funding since 7 October 2023, supplemental funding for regional operations, and an estimated additional cost of operations, it does not include any other economic costs," the report added.

"This figure includes the $17.9 billion the US government has approved in security assistance for Israeli military operations in Gaza and elsewhere since 7 October  – substantially more than in any other year since the US began granting military aid to Israel in 1959."

Yet the report describes how this is only a partial amount of the US. financial support provided during this war.