Leaders of the European Union (EU) urged Israel and Iran to de-escalate mounting tensions at a meeting in Brussels on Wednesday. Originally dedicated to sharpening the bloc's economic competitiveness, the EU summit was overshadowed by the recent turn of events in the Middle East.

The EU is eyeing fresh sanctions on Iran after the Islamic Republic fired over 300 missiles and drones toward Israel on Saturday. These were overwhelmingly shot down by Israeli air defenses, backed by a coalition of allies led by the United States.

Tehran said the attack was retaliation for an air strike on its embassy complex in Syria on April 1, which killed several senior officers from the Islamic Revolutionary Guard Corps (IRGC). Iran blames Israel for the strike. According to UN experts, both attacks may have broken international law.

On Wednesday, German Chancellor Olaf Scholz welcomed the fact that Israel had largely fended off the aerial strike, but appealed pointedly to his ally for restraint. "For us, it is important that this moment, this success for Israel, gets used for further de-escalation (…) and not to answer with a massive attack."

Drones under fire

Ahead of the two-day summit, EU foreign affairs chief Josep Borrell had already signaled that fresh sanctions on Iran's drone program were underway.

The idea is to expand an existing set of sanctions that aim to limit Iran's support for Russia's war of aggression in Ukraine. According to Borrell, the EU could expand this framework to include missiles, as well as deliveries to various Iranian proxy groups in the region.

Israel says it shot down the vast majority of drone and missile fire sent its way from Iran on Saturday

Many EU leaders expressed support for the move on Wednesday, including French President Emmanuel Macron, Germany's Scholz, Spanish Prime Minister Pedro Sanchez, Dutch Prime Minister Mark Rutte, and Belgian Prime Minister Alexander De Croo. "Our duty is to expand these sanctions," Macron said.

Speaking on condition of anonymity ahead of the summit, a senior EU official said an expansion of sanctions could be achieved within two weeks. The US announced plans for similar sanctions on Iranian drone production on Tuesday.

'Words are not enough'

Israel is pushing for tougher western sanctions, including more punitive measures on the IRGC, a military organization that was formed after the Islamic Revolution in Iran of 1979 and works in parallel with Iran's regular military.

"Words are not enough," Israel's Minister for Diaspora Affairs and Combating Antisemitism Amichai Chikli told reporters during a visit to Brussels on Wednesday. "We need to see decisive economic sanctions against Iran, against Iran Revolutionary Guard personnel, their leaders, their assets, all across the world, to shut down embassies."

"I don't think any Western state should have an embassy in Iran," he added.

The EU has already sanctioned a number of individual IRGC members on human rights grounds following domestic acts of repression. Amid last year's tough crackdown on anti-government protesters In Iran, the European Parliament pushed for listing the IRGC as a terrorist organization . At the time, the decision was not passed.

On Tuesday, Borrell said some EU member states had again raised the possibility of adding the IRGC to the EU's terrorism blacklist, but noted this would first require an EU court to determine the IRGC as such. Dutch Prime Ministers Rutte said that his country was among those supporting the move, but pointed to legal concerns that were slowing fellow leaders from following suit.

Is it enough?

The EU already has an extensive system of sanctions on Iran in place which respond to Iran's human rights violations, its assistance for Russia in its war in Ukraine, and alleged Iranian nuclear proliferation activities. These mean many individuals are subject to EU travel bans and asset freezes. The bloc has also imposed economic sanctions on Iran that prohibit the trade of arms and oil, among other goods.

Claude Rakisits, a visiting fellow at Brussel's Center for Security, Diplomacy and Strategy told DW he thought that targeting the IRGC would be more effective than drone-related sanctions. "The Islamic Revolutionary Guard should be put on the EU's terrorist list," he said. "It would cost them nothing, but it would send a very strong message."

Existing sanctions had not stopped Iran from delivering drones to Moscow, he added. In general, however, Rakisits was skeptical that this would change much. "Sanctions we know, historically, generally don't work," he noted.

Limits of EU influence

Ahead of the summit, several EU diplomats speaking on condition of anonymity seemed pessimistic about what leverage the bloc really had in the current flare of tensions between Iran and Israel. On the way into talks, many arriving leaders mainly focused their comments on Ukraine, where ammunition is running low and air defense is posing a major challenge.

In Rakisits' view, the best chance western leaders had of de-escalating Israeli-Iranian tensions was through Washington.

"The US would have to promise, to offer — for Netanyahu and his cabinet not to retaliate — they would have to promise something like an ironclad guarantee that there will be always a ready supply of military weapons, so that Americans can no longer use this as a lever to put pressure on the Israeli government," he said.

Escalation 'would serve no one,' Berlin warns

As the world watches to see how Israel will respond to Iran's attack, the EU and western allies are engaged in a flurry of diplomacy aimed at de-escalation.

Fears are high that the now six-month-old war between Israel and Palestinian militant group Hamas in Gaza could spill over into a war in the wider region.

Germany and the UK paid a visit to Israel in solidarity, but also to call for calm

On Wednesday, G7 foreign ministers meeting in Italy were also preoccupied by the crisis. German Foreign Minister Annalena Baerbock and her British counterpart David Cameron arrived there straight from Israel, where they had met with Prime Minister Benjamin Netanyahu.

Escalation "would serve no one," Baerbock said Wednesday in Israel, "not Israel's security, not the many dozens of hostages still in the hands of Hamas, not the suffering population of Gaza, not the many people in Iran who are themselves suffering under the regime, and not the third countries in the region who simply want to live in peace."

Israel vows to retaliate

Despite the calls for restraint from its western allies, including its closest backer the US, Israel has made clear it will respond to Iran's Saturday air strikes. Israel's designated War Cabinet met on Sunday and Monday to discuss appropriate measures, but so far, it remains unclear how Israel intends to respond.

"No state on Earth would suffer this kind of an assault and attack without a response," Chikli told DW. "I think we have the obligation to take serious steps and to make sure that these assaults will not happen again."