The Tenth Man Rule

The "Tenth Man Rule" from World War Z caught my attention not as a movie plot device, but as a profound insight into how institutions can protect themselves from their own blind spots.

Boeken explains how the Jewish people were slow to respond in Europe during the 1930s, equivocated during the escalation of Arab armaments in 1973 and paid for it both times. Now, a system exists where 10 high-ranking individuals are pooled to take every threat seriously. If nine agree to dismiss it, it is the duty of the tenth person to investigate further, even if it seems foolish.

This fictional doctrine turns out to have a real-world counterpart in the Israeli military, though with a different name and structure. According to IDF spokesperson Eytan Buchman:

After the Yom Kippur War (1973), the IDF's Intelligence Directorate created a Red Team, a devil's advocate team that can challenge prevalent assumptions within intelligence bodies.

The real version is even more sophisticated than the movie's version. Instead of just one dissenting voice, there's an entire unit dedicated to challenging conventional wisdom. What makes it effective isn't just the skepticism, it's the institutional power.

The officers have unfettered access to information through the military and are capable of tendering reports to senior levels - even reaching above the major general who commands military intelligence. The combination of access to information and the ability to challenge hypotheses by going above the command chain is critical.

This solves a fundamental problem with most organizational devil's advocacy: it's toothless. Someone raises an objection, the group discusses it politely, then proceeds with the original plan. But when the devil's advocate has independent access to decision-makers and can bypass the chain of command, the dynamic changes completely.

The unit's tag line is based on the classic "He who dares, wins" used by the SAS, and changed to "He who thinks, wins". The unit is also referred to occasionally as "Ipcha Mistabra", an Aramaic term popular in the Jewish Talmud that means "on the contrary, it appears that ..."

"He who thinks, wins" is brilliant. It positions intellectual courage, the willingness to question popular assumptions, as a form of bravery equivalent to physical courage. "On the contrary, it appears that..." gives them a formal framework for systematic contradiction.

The genius of institutionalizing dissent is that it removes the social cost of being the contrarian. When it's your job to find holes in the prevailing wisdom, you're not being difficult or disloyal, you're being professional. This creates space for the kind of thinking that's psychologically difficult but organisationally essential.

Intelligence is all about piecing together information amassed from a variety of sources. Like any puzzle in earlier stages, some pieces can be misinterpreted, which could lead to a cascading effect of incorrectly interpreted information.

This cascade effect is the real danger. One misinterpretation becomes the foundation for the next analysis, which becomes the basis for the next decision. Without systematic challenge, errors compound exponentially.

The broader lesson extends far beyond military intelligence. Every organization needs mechanisms to challenge its own assumptions. Product teams need someone asking whether users actually want what they're building. Strategy teams need someone questioning whether their market analysis is correct. Leadership teams need someone wondering whether their growth assumptions are realistic.

Most organisations rely on informal dissent ... hoping someone will speak up when they disagree. But informal dissent is fragile. It depends on individual courage, political capital, and social dynamics that often discourage the very feedback that's most needed.

Formal dissent, institutionalised skepticism with real authority, is much more reliable. It doesn't depend on heroes or rebels. It's just how the system works.

The question every leader should ask: Who is our tenth man? And do they have the access and authority to actually be heard when they disagree?