Saleh al-Arouri: Thousands attended the funeral of the deputy leader of Hamas in Beirut.

Crowds carried banners with his picture and waved Palestinian and Hamas flags amid music, prayers and loud gunfire. Al-Arouri was a key figure in Hamas's armed wing, the Izzedine al-Qassam Brigades, and a close associate of Hamas leader Ismail Haniyeh.

All over Lebanon, people watched the march on television and wondered what impact the killings would have on their country. Al-Arouri's killing was a blow not only to Hamas but also to Hezbollah, an ally of the powerful Iranian-backed Lebanese movement, and to the group's stronghold in Dahiyeh, outside the city.

Again, attention will be focused on the decision that the influential leader of Hezbollah, Hassan Nasrallah, will make. Less than 24 hours after the attack, he addressed his followers with plans to pay tribute to Iranian commander Qasem Soleimani, who was killed in a US drone strike four years ago. He couldn't ignore what had just happened in his backyard.

As usual, at an undisclosed location, Nasrallah described al-Arouri's killing as a "blatant Israeli aggression" that must not go unpunished. "If we believe that the enemy has waged war against Lebanon, then our fight will take place without borders or rules," he said. But most importantly, there was no overt threat to attack Israel.

The state has neither confirmed nor denied its involvement in the killings, nor provided details on how Hezbollah is responding.

One of Hezbollah's goals is the destruction of Israel. Israel is considered a stronger enemy than Hamas. Hezbollah has a vast arsenal that includes precision-guided missiles capable of striking deep into Israeli territory and tens of thousands of well-trained and battle-hardened fighters.

Since the war between Israel and Hamas began last October, Hezbollah has attacked northern Israel almost daily, describing its actions as support for Palestinian groups. Israeli forces have retaliated, but so far the violence has been limited to the Lebanese-Israeli border.

Hezbollah has calculated steps to prevent an all-out war with Israel, but there are no signs that this strategy may change. Many people here still remember the months-long conflict between Israel and Hezbollah in 2006 and the fact that public support for a military conflict was virtually non-existent as Lebanon suffered a massive economic crisis.

Israeli authorities warned Hezbollah not to escalate the conflict. Defense Minister Yoav Gallant previously said the Israeli military could do to Beirut what it did to Gaza. Some senior Israeli officials have called for further action against the group to address the threat to northern communities that have been evacuated as Hezbollah attacks continue.

Nasrallah is scheduled to address supporters again on Friday. His recent speech may be an indication that he wants to avoid a bigger conflict with Israel, for whatever reason. However, it is not yet known if he is responding to the attack in Beirut. But any response will likely be coordinated to avoid strong Israeli retaliation.