Kindervag's 2010 Zero Trust pitch recast Cheswick's 1990 'chewy centre' metaphor — coined as a criticism — into a naive ideal practitioners had supposedly wanted

The "M&M model" — a network with a hard crunchy shell (the firewall) and a soft chewy centre (the trusted interior) — is usually told as the naive design ideal that Zero Trust corrected. Per Spencer & Pizio (2024), that history inverts the metaphor's original intent. Bill Cheswick coined "chewy centre" in his 1990 AT&T gateway paper specifically to criticize the vulnerable interior of perimeter-defended networks, not to endorse it. When Forrester analyst John Kindervag popularized Zero Trust in 2010, he retold the M&M model as something practitioners had once wanted and Zero Trust supersedes — manufacturing a naive past for Zero Trust to be the correction to. The source paper frames this as Kindervag writing from his own experience rather than from Cheswick's actual text.

This is a retrospective-framing move: a critical metaphor gets re-narrated, twenty years later, as the position its critique is credited with overturning. The pattern recurs across the vault's history-of-ideas material — compare myth-werbos-invented-backpropagation (a real contributor's work retold as sole-origin because the vacuum left by an uncited paper invited a single-inventor story) and claim-mabillon-1681-founded-diplomatics-to-refute-forgery-charge (authenticating a claimed origin against the dated primary text rather than the received telling).