Two Bombs a Year: Robert Webber and the Dimona Secret

By Eleanor Voss · September 27, 2026

Kept secret for decades, a 1965 debriefing shows the U.S. knew the Dimona reactor was a weapons project while officials worked to keep the IAEA out of the Negev.

A government in Jerusalem faced collapse, and a secret in the desert threatened to trigger a regional arms race. The cost of maintaining the fiction of a peaceful reactor was a calculated blindness that allowed Israel to build the foundation of a nuclear arsenal while the United States managed the optics.

This account is reconstructed from the archive's curated description of the debriefing rather than the original pages. The record is a November 18, 1965, report by William D. Wolle, an official in the Office of Near East Economic Affairs—the arm of the State Department that managed technical and economic diplomacy in the region—who debriefed the American embassy's science attaché in Tel Aviv.

"No sense except as a weapons project"

Robert Webber, the science attaché tasked with monitoring Israel's technical capabilities, did not believe in the official narrative of the Shimon Peres Negev Nuclear Research Center. Located 13 kilometres southeast of Dimona, a city in the Negev desert, the facility was presented as a civilian venture. Webber saw through the facade. During his briefing in Washington, Webber argued that the Dimona project made "no sense except as the basis for a [future] weapons project" (Wolle, 1965).

Webber's assessment was grounded in the hardware. He reported that the facility contained a "semi-pilot [reprocessing] plant installation" and the specific equipment needed to "handle plutonium and irradiated rods" (Wolle, 1965). To Webber, the mathematics were simple and devastating: a 26-megawatt reactor could produce two bombs a year. While he accepted the prevailing American view that weapons were not being actively produced in 1965, he insisted that Israel "was building up its basis for future weapons production" (Wolle, 1965).

This creates a sharp line between the field and the capital. Webber was on the ground in the Negev, observing the flow of materials and the layout of the plant. His conclusion was not a guess but a technical derivation. Yet, his findings were met with a wall of institutional resistance in Washington.

Document imagery from nsarchive.gwu.edu From the files: nsarchive.gwu.edu

The Stabler Disagreement

The record highlights a fundamental rift between the diplomatic corps and the technical regulators. Webber noted that while U.S. inspectors expressed satisfaction with the site, he remained unconvinced. He stated explicitly that Dimona was "more of a military project than Mr. Stabler of the AEC is willing to accept" (Wolle, 1965). Mr. Stabler, an official with the Atomic Energy Commission—the agency then responsible for the U.S. nuclear weapons program and civilian energy—represented the official Washington line: that Dimona was a peaceful project.

This disagreement was not a conflict of data, but of will. Webber pointed out that U.S. inspections were flawed because they lacked access to records on the flow of uranium, a transparency the Israelis strictly disallowed (Wolle, 1965). Stabler's refusal to accept the military nature of the project provided the necessary diplomatic cover. If the AEC, the primary technical authority, refused to label Dimona a weapons site, the State Department could avoid the political fallout of demanding a shutdown or an international takeover.

The Shield of Bilateralism

The U.S. chose to handle the inspection crisis through private channels rather than through the International Atomic Energy Agency (IAEA), the UN-system organization tasked with preventing military nuclear use. The record is blunt about the outcome of this choice: Israel was not going to accept an IAEA role "no matter what we threaten" (Wolle, 1965).

By insisting on bilateral inspections, the U.S. effectively shielded Israel from the IAEA. This arrangement turned the inspection process into a tool of political management rather than non-proliferation. Webber admitted that the inspections provided the U.S. with a "psychological advantage" (Wolle, 1965), but this advantage belonged to the inspectors, not the world. It allowed Washington to claim it had a handle on the situation while ensuring no international body could legally enter the site and confirm the presence of a weapons program.

This secrecy was fragile. The record notes that a leak to the New York Times via journalist John Finney had already damaged the U.S. government's position. The leak convinced the government of Levi Eshkol—the Prime Minister and former Defense Minister who led the Israeli Labor Party—that the U.S. could not be trusted with the secrecy of future inspections (Wolle, 1965). Webber warned that the inspection issue was so volatile that the Eshkol government "could be overthrown by the issue" (Wolle, 1965). The stakes were not just nuclear; they were existential for the Israeli premiership.

The Missing Link

Despite the AEC's reluctance, Webber remained certain that the technical gap was being closed. While there was "no sign" of a plutonium separation plant at Dimona itself, Webber believed that "Israel is currently active somewhere and somehow on this missing link" (Wolle, 1965). He was looking for the facility that would turn irradiated uranium into weapon-grade plutonium.

Webber's intuition extended to the eventual test. He predicted that if Israel tested a bomb, it would be underground, specifically pointing to "the large natural depression southeast of Dimona (HaMaktesh Haqatan)" (Wolle, 1965). He noted that Israel likely already possessed the "requisite test equipment, high-speed cameras, etc." (Wolle, 1965). The record depicts a man watching a countdown that his superiors were pretending hadn't started.

The Institutional Brake

The pattern suggests that the disagreement between Webber and Stabler was not a technical dispute over reactor capacity, but a policy-driven "institutional brake." The desk's reading is that the AEC's refusal to acknowledge the military nature of Dimona was designed to maintain plausible deniability. By keeping the technical assessment in the realm of "disagreement" rather than "fact," Washington could maintain its relationship with the Eshkol government without appearing to endorse proliferation.

If this file is shaped the way it looks, the bilateral inspection regime was an intentional shield used to preclude IAEA involvement. The U.S. traded international transparency for private leverage, ensuring that the secret of Dimona remained a bilateral arrangement that could be leveraged to stabilize the Israeli government. The "psychological advantage" mentioned by Webber was not about stopping a bomb, but about managing a client state's trajectory in the dark.

The gap between Webber's certainty about the "missing link" and the official lack of evidence suggests that the actual operational intelligence—the clandestine data from the CIA or NSA—was kept in a separate classification stream. The State Department was maintained in a state of managed ignorance to ensure that diplomats could continue to negotiate in good faith while the intelligence community watched the plutonium separation plants being built. The result was a world where the U.S. could claim it was preventing a nuclear race in the Middle East while simultaneously providing the diplomatic cover that made that race possible. The cost was a permanent precedent of nuclear opacity in the region, paid for by the truth that Robert Webber tried to tell in a Washington briefing room.