CIA Director William Burns warned Monday of the potential for simmering clashes in the Middle East to spread across the region even as, he said, the U.S. intelligence community had assessed the leaders of Iran and Israel are not looking for “all-out conflict.”

“[W]e face the very real danger of a further regional escalation of conflict,” Burns said during a moderated question-and-answer session at the annual Cipher Brief threat conference in Sea Island, Georgia. He said Israel’s leadership was “weighing very carefully” how it would respond to Iran’s ballistic missile attack last week, but warned that “misjudgments” could still lead to an inadvertent escalatory spiral.

“The Middle East is a place where complicated stuff happens all the time,” Burns said.

A combination of robust intelligence-sharing between the U.S. and Israel, and “strong” integrated air defenses, allowed for the defeat of the large-scale missile attack from Iran on Oct. 1, Burns said. The attack exposed some “limitations” in Tehran’s military capabilities, but he said “that’s not to suggest that those capabilities are still not quite potent and something that not only Israel, but the United States, needs to take very seriously, too.”

The former senior diplomat —who played a key role in negotiating the 2015 nuclear deal that put constraints on Iran’s uranium enrichment program— said his agency had nonetheless not seen indications that Iran’s Supreme Leader Ayatollah Ali Khamenei had decided to accelerate his country’s efforts to produce a nuclear weapon.

“[W]e do not see evidence today that the Supreme Leader has reversed the decision that he took at the end of 2003 to suspend the weaponization program,” Burns said. He acknowledged, however, that Iran was in a “much closer position” to create a single bomb’s worth of weapons-grade material, with a breakout time now at “a week or a little more.”

Speaking one year after Hamas militants stormed into southern Israel, killing more than 1,200 Israelis and kidnapping more than 250, Burns —who had for the past year been leading diplomatic negotiations alongside counterparts from Qatar, Egypt and Israel— expressed hope that a diplomatic deal could still be struck for a ceasefire and to secure the release of remaining hostages in Gaza.

“We’ve come close at least a couple of times, but it’s been very elusive,” he said. Talks on Gaza had come to a standstill in recent weeks as, U.S. officials said, Hamas leader Yahya Sinwar had stopped responding to updated proposals.

“[W]hat’s at stake in Gaza is shaped by political will,” Burns stressed. “In the end, it’s not just about brackets in texts or creative formulas when you’re trying to negotiate a hostage and ceasefire deal. It’s about leaders who ultimately have to recognize that enough is enough, that perfect is rarely on the menu, especially in the Middle East.”

“And then you’ve got to go make hard choices and some compromises in the interest of a longer-term strategic stability as well,” he said.