(NewsNation) — After the deadliest attack in Israel in decades, questions are being raised about how U.S. and Israeli intelligence services missed the warning signs of an attack by Hamas.

Former CIA officer Tracy Walder spoke to NewsNation regarding the attack, which has led to a declaration of war from Israel and left hundreds of people dead and thousands injured.

Walder said one complicating factor was a lack of political unity after the election of Israeli Prime Minister Benjamin Netanyahu, a controversial figure.

“Thousands of people in their military service and their intelligence service actually resigned in protest,” Walder said. “That has created a really big breakdown.”

In terms of the U.S., Walder notes that U.S. agencies have sometimes relied too heavily on Israel to share their own intelligence information rather than gathering information independently.

“As a result, we both kind of miss the ball,” she said.

Israel’s declaration of war and Netanyahu’s vow to lay siege to the Gaza Strip, home to more than two million Palestinians, have led to calls for de-escalation.

President Joe Biden, however, pledged U.S. support for Israel and the U.S. military is moving a carrier group into the region.

Walder agreed there should be some de-escalation needed to avoid another world war.

“I don’t necessarily want to see Iran getting involved,” she said. “I don’t think Israel is going to directly attack Iran, but I do think they’re going to attack perhaps their interests overseas.”