Hezbollah's involvement in the Syrian civil war, particularly its support of Bashar al-Assad in suppressing an armed uprising in 2012, presented Israel with an opportunity to observe the group's evolution closely, The Financial Times reported. 

As Hezbollah’s fighters became more battle-hardened, Israel was able to gather a comprehensive "intelligence picture" of the organization. This included tracking key figures, promotions within the ranks, signs of corruption, and unexplained travel movements. Although Hezbollah’s involvement in Syria strengthened its military capabilities, the ongoing conflict also made it more vulnerable to infiltration by Israeli spies and susceptible to potential defectors.

The Syrian conflict also generated a wealth of publicly available information, which Israeli intelligence, aided by advanced algorithms, was able to analyze. One key source of data was Hezbollah’s “Martyr Posters,” which often included details about the deceased fighter’s hometown, the location of their death, and clues about their social connections, as seen on social media. Funerals also became a valuable resource for Israeli spies, sometimes bringing senior Hezbollah leaders into public view, even if briefly.

According to Randa Slim, a program director at the Middle East Institute, Hezbollah’s expansion into Syria weakened its internal controls, creating openings for espionage. 

"Syria was the beginning of the expansion of Hezbollah," Slim noted. "That weakened their internal control mechanisms and opened the door for infiltration on a big level."

A former high-ranking Lebanese politician noted that Hezbollah’s support for Assad came at a cost. 

“The price of their support for Assad was exposure,” the politician explained. Hezbollah, a traditionally secretive group, was forced to collaborate with the corrupt Syrian intelligence apparatus and Russian intelligence, which were both closely monitored by Western agencies. This change in operations marked a departure from Hezbollah’s disciplined past, where it had previously managed to evade Israel's formidable intelligence network.

Despite Hezbollah’s earlier successes in Lebanon—such as its ability to outsmart Israel by intercepting unencrypted drone feeds in the 1990s—Israel’s intelligence capabilities continued to evolve. Advances in surveillance technology, including spy satellites, drones, and cyber-hacking tools, gave Israel a growing advantage over Hezbollah. Unit 9900, a specialized division within Israeli intelligence, developed algorithms to analyze massive amounts of visual data, helping identify potential threats, from roadside explosives to underground bunkers.

Once a Hezbollah operative was identified, Israel closely monitored their daily movements, compiling vast amounts of data from various sources. This included hacking into cell phones, CCTV camera feeds, and even smart devices like modern TVs. Any deviation from normal routines would trigger alerts for intelligence officers to investigate, allowing Israel to track mid-level commanders of Hezbollah’s anti-tank units and anticipate their actions.

Through years of meticulous intelligence gathering, Israel built an extensive database of Hezbollah targets. When conflict erupted, Israeli warplanes were able to strike thousands of suspected Hezbollah positions within the first three days of their air campaign, as revealed by the Israeli army. 

A former Israeli official emphasized the scale of these efforts, saying, "We had a lot of intelligence stored waiting to be used. We could have used these capabilities way earlier in this war, but we didn’t."