Explainer - Why the US is stopping some bomb shipments to Israel

The suspension comes as Israeli Prime Minister Benjamin Netanyahu continues a military assault on the Palestinian city of Rafah, over the objections of U.S. President Joe Biden.

Here's what we know so far: WHAT BOMBS WERE BLOCKED?

Washington paused one shipment consisting of 1,800 2,000-pound (907-kg) bombs and 1,700 500-pound bombs, according to U.S. officials.

Four sources said the shipments, which have been delayed for at least two weeks, involved Boeing-made Joint Direct Attack Munitions, which convert dumb bombs into precision-guided ones, as well as Small Diameter Bombs (SDB-1). The SDB-1 is a precision guided glide bomb that packs 250 pounds of explosive.

They were part of an earlier approved shipment to Israel, not the recent $95 billion supplemental aid package the U.S. Congress passed in April.

WHY IS THE U.S. BLOCKING THESE BOMBS?

The U.S. is reviewing "near term security assistance," Defense Secretary Lloyd Austin told a Senate hearing on Wednesday "in the context of unfolding events in Rafah."

"We've been very clear...from the very beginning that Israel shouldn't launch a major attack into Rafah without accounting for and protecting the civilians that are in that battlespace," Austin said. More than one million Palestinian civilians have sought shelter in Rafah, many previously displaced from other parts of Gaza following Israel's orders to evacuate from there.

The U.S. decision was taken due to concerns about the "end-use of the 2,000-pound bombs and the impact they could have in dense urban settings as we have seen in other parts of Gaza," said a U.S. official speaking on condition of anonymity. The U.S. had carefully reviewed the delivery of weapons that might be used in Rafah, the official said.

WHEN WAS THE DECISION MADE? WAS BIDEN INVOLVED?

The decision was made last week, U.S. officials said. Biden was directly involved. Biden confirmed the pause personally in a CNN interview Wednesday.

"Civilians have been killed in Gaza as a consequence of those bombs and other ways in which they go after population centers," he said when asked about 2,000-pound bombs sent to Israel.

WHAT KIND OF DAMAGE CAN 2,000-POUND BOMBS CAUSE?

Large bombs like 2,000-pound bombs have an impact over a wide area. According to the United Nations, "The pressure from the explosion can rupture lungs, burst sinus cavities and tear off limbs hundreds of meters from the blast site."

The International Commission for the Red Cross in a 2022 reports the use of wide area explosives in a densely populated area "is very likely to have indiscriminate effects or violate the principle of proportionality."

WHAT WAS ISRAEL'S RESPONSE?

Israel denies targeting Palestinian civilians, saying its sole interest is to annihilate Hamas and that it takes all precautions to avoid unnecessary death.

After the news broke Tuesday in Washington, a senior Israeli official declined to confirm the report. "If we have to fight with our fingernails, then we'll do what we have to do," the source said. A military spokesperson said any disagreements were resolved in private.

WERE THESE BOMBS LEGAL FOR ISRAEL TO USE IN GAZA?

That is a matter of heated debate.

International humanitarian law does not explicitly ban aerial bombing in densely populated areas, however civilians cannot be targets and a specific military aim must be proportionate to possible civilian casualties or damage.

WHAT DOES THE INTERNATIONAL CRIMINAL COURT SAY?

The statute of the International Criminal Court, which is investigating the Israel-Gaza war, lists as a war crime intentionally launching an attack when it is known that civilian death or damage will be "clearly excessive" compared to any direct military advantage.

HAS THE US WITHHELD MILITARY AID FROM ISRAEL BEFORE?

Yes, in 1982. President Ronald Reagan imposed a six-year ban on cluster weapons sales to Israel after a Congressional investigation found that Israel had used them in populated areas during its 1982 invasion of Lebanon.

Israel's use of U.S.-made cluster bombs was reviewed under President George W. Bush, over concerns they were used during a 2006 war with Hezbollah guerrillas in Lebanon.