The "hardest decision" for pre-emptive war

Or, what is the intelligence?

Israel’s decision to launch pre-emptive strikes against Iran, targeting its nuclear capabilities, missile sites, military leadership and nuclear scientists, rested on two kinds of intelligence.

One was an ability, presumably led by Mossad, to achieve remarkably high levels of intelligence on its targets, on Iran’s air defence capabilities, and to support military preparations with the near-certainty of achieving surprise.

Capitation strikes of the kind leveled against Iran’s military leaders and nuclear scientists require precision intelligence to be successful. The assumption must be that Israeli intelligence was able to muster a powerful cocktail of signals intelligence, imagery intelligence and human sources to achieve its objectives.

Similarly, nuclear and ballistic missile sites, to be turned into targets, need more than just geo-location. They need high degrees of intelligence to help the IDF (Israeli defence forces) choose the best weapons packages against them, particularly any targets located in underground facilities or bunkers.

That Mossad was able to smuggle drones into Iran and pre-position them for strikes mimics Ukraine’s ability in its targeting of Russian strategic bombers in its dramatic June 1 attack. It also indicates a strong awareness of vulnerabilities in Iran’s internal surveillance and security system.

The evidence of remarkable success with tactical intelligence will go far to restore Mossad’s credibility after the failures of the October 7 Hamas assault.

What this kind of intelligence success cannot tell us concerns the bigger question of Israeli strategic assessments of the Iranian nuclear weapons threat. We don’t know the details of that assessment and cannot judge how accurate it might have been. But much may ride on the quality of Israeli strategic intelligence, not least in providing legitimacy for the pre-emptive strikes against Iran.

An important and singular clue to the Israeli threat perception came from the Israeli Prime Minister. In announcing the military strikes on Iran, codenamed “Rising Lion,” Benjamin Netanyahu laid out his justification for launching a pre-emptive war and revealed some, at least, of the core elements of Israel’s strategic threat assessment. ^[i]

One element concerned the imminence of the threat posed by Iran’s nuclear weapons program. Netanyahu told the world that if Israel had not taken miliary action,” Iran could produce a nuclear weapon in a very short time.” How short?—maybe a year, maybe within a few months. The time scale appears elastic. This matters in any calculation of a pre-emptive war.

A second core element was a picture of the magnitude of the Iranian nuclear threat.

In his address, the Israeli Prime Minister claimed that in “recent years” Iran had produced enough highly enriched uranium (HEU) for 9 atom bombs. He added that in “recent months” Iran had taken steps to “weaponize” this HEU. The precise nature of these “steps” to “weaponize” was not made clear.

How might a handful of nuclear weapons be used by Iran? A nuclear weapon needs a delivery system. Netanyahu claimed that “soon” Iranian missiles could carry nuclear warheads. How soon? Unclear. The Israeli PM also made the astonishing claim that Iran is planning to give nuclear weapons to its terrorist proxies.

Why might Iran turn to nuclear weapons? Netanyahu stated that it was a new policy, developed out of the failure of an old policy to, as he put it, surround Israel with a “ring of fire” based on threats from proxy groups like Hezbollah and Hamas, and the Assad regime in Syria. A weakened Iran, no longer able to mobilize its proxies because of Israeli actions against them, turned instead in a different direction—counting on the development of its nuclear weapons to destroy Israel, even though its nuclear arsenal would be dwarfed by that possessed by Israel.

Netanyahu knows that a pre-emptive war needs a strong justification. He called it the “hardest decision” to “thwart a danger before it is fully realized,” but argued that Israel was acting on the lessons of history, especially the lessons of the 1930s and the failed appeasement of Nazi Germany, which resulted in World War Two and mass death, including of six million Jews in the Holocaust. Israel, he said, was determined to prevent a nuclear holocaust.

If Netanyahu was accurately conveying, at least in the round, the Israeli strategic threat assessment of the Iranian nuclear weapons program, these things stand out:

an elastic definition of the imminence of the threat;

vagueness about how soon Iran might be able to place nuclear warheads on ballistic missiles;

an outlandish claim about providing nuclear weapons to proxy terrorist groups;

a suggestion of a new Iranian strategic policy.

We do not know, of course, the extent to which any Israeli threat assessment actually drives Netanyahu’s policy or the extent to which Netanyahu truthfully conveyed it in his public address. Opportunity may be a bigger factor, with a weakened Iran and an ability to bring the US onside by suggesting that Iran is not serious about negotiations to end its nuclear program. Tactical intelligence and the ability to achieve surprise plays into the opportunity.

In his seminal work on Just War theory, Michael Walzer sets out four conditions to justify pre-emptive war. They include: imminent threat; the intention to harm the defending state; military preparations requiring a response; and action from necessity. ^[ii]

Benjamin Netanyahu claimed that Iran presented a “clear and present danger” to the existence of Israel. This speaks directly to the fourth of Walzer’s criteria. The necessity of conducting pre-emptive war rests on a belief that waiting would only increase the risk. Of the Walzer criteria, the available evidence from the Netanyahu address appears weakest with respect to the imminence of the Iranian threat, given the time-lines and language used by the Israeli PM, and the notion that Iran was making military preparations to attack Israel. On the other hand, there is plenty of supporting evidence of Iran’s intention, embedded in vitriolic leadership rhetoric, to harm Israel.

The Israeli attack may or may not pass the test of pre-emptive war criteria. We may, or may not, ultimately learn the truth about Iranian preparations to cross the line into the preparation of a nuclear weapons program. The truth may be supportive of the Israeli decision; it may completely undermine it, as was the case following the US-led invasion of Saddam Hussein’s Iraq in 2003, when no active weapons of mass destruction program was found. Netanyahu may risk a repeat of a closer history than that of the 1930s.

Israel’s closest ally, the United States, will, of course, possess its own intelligence reading of the status and threat posed by the Iranian nuclear weapons program. Both the United States and Israel align in a determination that Iran must not be allowed to develop nuclear weapons. That was the subject of the negotiations between the US and Iran, now derailed.

It is noteworthy that the most recent US annual threat assessment, presented to Congress in late March 2025, contained a depiction of the Iranian menace to the region, including US bases and interests. But on the nuclear issue it reported that “the IC [intelligence community] continues to assess that Iran is not building a nuclear weapon and Supreme leader Khomeini has not authorized the nuclear weapons program he suspended in 2003.” The Director of National Intelligence promised that US intelligence would continue to monitor the situation closely. ^[iii]

This baseline US intelligence assessment is of long-standing. On occasion the supporting intelligence has surfaced, notably in December 2007. A redacted version of a November 2007 National Intelligence Estimate (NIE) on “Iran’s Nuclear Intentions and Capabilities” was made public and created what one authoritative study called a “firestorm of controversy.” ^[iv] It was a nuanced report that was accompanied by a very un-nuanced political reaction.

The key judgements in that 2007 NIE included the statement that:

“Judge with high confidence that in fall 2003, Tehran halted its nuclear weapons program.”

“Assess with moderate confidence Tehran has not restarted its nuclear weapons program as of mid-2007, but we do not know whether it currently intends to develop nuclear weapons”

“Judge with high confidence that the halt was directed primarily in response to increasing international scrutiny and pressure resulting from the exposure of Iran’s previously undeclared nuclear work.”

“ Assess with moderate-to-high confidence that Tehran at a minimum is keeping open the option to develop nuclear weapons.”

The NIE also made the point that “in our judgment, only an Iranian political decision to abandon a nuclear weapons objective would plausibly keep Iran from eventually producing nuclear weapons—and such a decision is inherently reversible.” ^[v]

That was 2007. But elements of the intelligence assessment seem to remain current as of March 2025.

This example of what became a controversial intelligence report reminds us that even superpower intelligence can rarely be definitive about a foreign state’s intentions and capabilities and has no special gifts for prediction. The same is presumably true for Mossad, whatever the brilliance of its tactical intelligence achievements against the Iranian target.

The NIE is also a reminder that intelligence reporting will rarely if ever meet the very high bar of providing evidence to meet a just war/pre-emptive calculation.

The stinger in the tail of the 2007 NIE is the reflection that only an Iranian political decision to abandon nuclear weapons program would be sufficient, and may not be lasting. Such a political decision was at the heart of the US-brokered negotiations. It may now be off the table.

In any case, Benjamin Netanyahu signalled in his address that he had a different political objective in mind. Not to pressure the Iranian regime to agree to give up nuclear weapons, but to use a surprise attack and military force to engineer regime change in Iran.

Here is what he said:

“I have a message for the brave people of Iran. Our fight is not your fight. I believe the day of your liberation is near.”

It is very unlikely that that belief is rooted in intelligence.

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^[i] Statement by PM Netanyahu, June 12, 2025,

^[ii] Michael Walzer, Just and Unjust War (Basic Books, first edition 1977)

^[iii] Opening statement as delivered by the Honorable Tulsi Gabbard, Director of National Intelligence, “Annual Threat assessment of the US intelligence community,” March 26, 2025, https://www.odni.gov/files/ODNI/documents/assessments/ATA-2025-Testimony-As-Prepared.pdf

^[iv] Gregory F. Treverton, “CIA support to Policy Makers: The 2007 National Intelligence Estimate on Iran’s Nuclear Intentions and Capabilities,” CIA Center for the Study of Intelligence, May 2013, https://www.cia.gov/resources/csi/static/2007-Iran-Nuclear-Intentions.pdf; Thomas Fingar, Reducing Uncertainty: Intelligence Analysis and National Security (Stanford University Press, 2011), pp. 115-125 discussing the 2007 NIE which he directed.

^[v] Treverton, Appendix A, “Unclassified Key Judgments