The confrontation between Israel and the United States on one side and Iran on the other did not begin with the recent visible strikes. It is the escalation of a long-standing covert campaign that crossed into open warfare after the confirmed death of Iran’s supreme leader, Ayatollah Ali Khamenei, during the opening wave of attacks.
For years the conflict played out in shadows: assassinations, sabotage, cyberattacks and clandestine infiltration that Tehran frequently attributed to Israeli intelligence, often implying American involvement. Those operations were typically deniable—Iran blamed foreign services, Israel largely stayed silent and Washington publicly distanced itself—while Iranian leaders repeatedly promised retaliation.
A discernible pattern emerged across more than a decade of targeted killings connected to Iran’s nuclear and military apparatus. In January 2010 Masoud Ali‑Mohammadi, a Tehran University physics professor linked to the Atomic Energy Organization, was killed by a remote‑controlled bomb attached to his car; Iranian officials pointed at Israeli intelligence. That November, Majid Shahriari, a nuclear physicist, died after a magnetic bomb detonated on his vehicle. In July 2011 Darioush Rezaeinejad was gunned down outside his home, and in January 2012 Mostafa Ahmadi Roshan was killed by a similar device. Together, these attacks signaled a sustained campaign against scientists and technicians tied to Iran’s nuclear programs.
Israeli leaders often kept public silence, though in 2012 then‑defense minister Ehud Barak said he was “not shedding tears” for the slain scientists, a comment widely read as tacit approval. Western intelligence officials, speaking anonymously to the media, commonly suspected Israeli responsibility for several of the attacks, but governments avoided formal admissions.
The tempo of the covert offensive rose in November 2020 with the assassination of Mohsen Fakhrizadeh, whom Western and Iranian officials described as a senior figure in Iran’s past nuclear weapons research and whom then‑Israeli prime minister Benjamin Netanyahu had publicly named in 2018. The operation near Tehran reportedly used remote‑operated weaponry. Iran accused Israel of directing the killing and later announced arrests of suspects allegedly connected to Mossad. Fakhrizadeh’s death came even as the Biden administration pursued renewed diplomacy, underscoring the gulf between public foreign policy and clandestine operations.
Targets were not limited to scientists. In January 2020 the United States carried out a high‑profile strike that killed Qassem Soleimani, commander of the IRGC’s Quds Force, in Baghdad. Tehran treated that strike as part of the same pressure campaign, a moment when the shadow conflict briefly surfaced as open confrontation. In May 2022 Colonel Hassan Sayyad Khodaei, described by Iranian state media as a Quds Force operative, was shot dead in Tehran; Iran blamed “elements linked to global arrogance,” a phrase often used to refer to Israel and the United States, while international reporting cited unnamed intelligence sources pointing to Israeli involvement.
Sabotage and cyber operations were another persistent element. The 2010 Stuxnet attack, later widely reported as a joint US‑Israeli effort, damaged centrifuges at Natanz. Iran experienced a string of unexplained explosions and incidents at nuclear sites it blamed on foreign meddling. In 2018, Israeli operatives reportedly removed a large cache of Iranian nuclear documents from a Tehran facility; Netanyahu publicly presented the archive as proof of concealed activity. Tehran acknowledged the break‑in but minimized its importance.
Tehran has also accused Mossad of recruiting Iranian nationals to conduct surveillance and operations inside the country. State media aired arrests and alleged confessions of “Mossad‑linked agents,” though human rights groups cautioned that such confessions could be coerced. Israeli media, citing unnamed security sources, reported extensive efforts to infiltrate Iranian networks.
For much of the past decade the confrontation remained calibrated and deniable. Israel conducted repeated airstrikes in Syria aimed at disrupting Iranian arms transfers to Hezbollah and other proxies, actions it rarely admitted. Iran expanded its presence across Iraq, Syria, Lebanon and Yemen, strengthening regional proxies and networks. Each side’s measures hardened rhetoric and narrowed diplomatic options: Israeli leaders warned they would act “anywhere” to prevent Iran from obtaining nuclear capability, US officials reiterated support for Israel, and Iran’s supreme leader denounced Israel and vowed retaliation.
As assassinations, sabotage, sanctions and threats accumulated, the boundary between covert confrontation and declared war thinned. The confirmed killing of Khamenei during the opening strikes represents the collapse of that line. What began as deniable operations in laboratories, on Tehran’s streets and inside intelligence networks has now erupted into overt state‑to‑state warfare. The missiles and overt military actions across the region are not the origin but the public phase of a conflict that has been building in shadow for years.
