The conflict between Israel and the United States on one side and the Islamic Republic of Iran on the other did not begin with the recent aerial strikes. It is the culmination of a long-running shadow campaign that entered a new phase with the confirmed death of Iran’s supreme leader, Ayatollah Ali Khamenei, during the opening wave of attacks.
For years the campaign operated in the shadows: assassinations, sabotage, cyber‑intrusion and covert penetration attributed by Tehran to Israeli intelligence, often with alleged American backing. These actions were usually deniable — Iran blamed foreign intelligence services, while Israel rarely confirmed and Washington publicly distanced itself. Tehran repeatedly vowed revenge.
The pattern became visible over a decade of targeted killings. In January 2010, Masoud Ali‑Mohammadi, a Tehran University professor and consultant to Iran’s Atomic Energy Organisation, was killed by a remote‑controlled bomb on his car; Iranian officials blamed Israeli intelligence. That November, Majid Shahriari, a nuclear physicist involved in uranium enrichment research, died after a magnetic bomb was attached to his car. In July 2011 Darioush Rezaeinejad was shot outside his home, and in January 2012 Mostafa Ahmadi Roshan was killed by a similar device. Collectively, these incidents signalled a sustained campaign against figures linked to Iran’s nuclear programme.
Israeli leaders kept public silence, though in 2012 defence minister Ehud Barak said he was “not shedding tears” for the slain scientists, a remark taken as tacit approval. Western intelligence officials, speaking to media on condition of anonymity, widely believed Israeli services were responsible for several attacks, but no official admissions were made.
The tempo intensified in November 2020 when Mohsen Fakhrizadeh — described by Western and Iranian officials as a senior figure in Iran’s past nuclear weapons research and publicly identified by Israeli prime minister Benjamin Netanyahu in 2018 — was killed near Tehran. The operation used remote‑operated weaponry; Iran accused Israel of directing it and announced arrests of suspects said to be linked to Mossad. The assassination occurred amid renewed US diplomatic engagement under President Joe Biden, underlining the gulf between covert action and public diplomacy.
The campaign’s targets were not limited to scientists. In January 2020 the United States carried out an overt strike that killed Qassem Soleimani, commander of the IRGC’s Quds Force, in Baghdad. Tehran viewed that strike as part of the broader pressure campaign, a moment when the shadow conflict briefly surfaced into open confrontation. In May 2022 Colonel Hassan Sayyad Khodaei, described by Iranian state news as a Quds Force member, was shot dead in Tehran; Iran blamed “elements linked to global arrogance,” a phrase commonly referring to Israel and the United States, and international reporting cited unnamed intelligence sources pointing to Israeli involvement.
Sabotage and cyber operations were another strand. The 2010 Stuxnet cyber‑attack, later widely attributed in reporting to joint US‑Israeli efforts, damaged centrifuges at Natanz. Unexplained explosions and incidents at nuclear sites were blamed by Iranian authorities on foreign interference. In 2018 Israeli operatives reportedly removed a large cache of Iranian nuclear documents from a Tehran facility; Netanyahu publicly displayed the archive as evidence of concealed activity. Tehran acknowledged the break‑in but downplayed its significance.
Tehran also accused Mossad of recruiting Iranian nationals to conduct surveillance and operations inside Iran. State media broadcast arrests and alleged confessions of “Mossad‑linked agents,” though rights groups warned such confessions may have been coerced. Israeli media, citing unnamed security sources, reported extensive infiltration efforts.
For much of the past decade the conflict remained calibrated and deniable. Israel conducted numerous airstrikes in Syria targeting Iranian arms transfers to Hezbollah and other proxies, actions it seldom formally acknowledged. Iran expanded its regional footprint across Iraq, Syria, Lebanon and Yemen. Each side’s actions hardened rhetoric and narrowed diplomatic space: Netanyahu said Israel would act “anywhere” to stop Iran’s nuclear ambitions, US officials reiterated support for Israel, and Khamenei repeatedly denounced Israel and vowed retaliation.
As assassinations, sabotage, sanctions and threats accumulated, the line between covert confrontation and open war thinned. The confirmed killing of Khamenei during the opening strikes marks the collapse of that boundary. 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 visible military actions across the region represent not the start but the public phase of a conflict that was long in the making.
