This book asks one question of one practice. When artificial intelligence sits on both sides of the table, in the tooling that emulates an adversary and in the tooling that detects and responds, does the loop between the red team and the blue team still tell an organisation whether it would have seen and stopped an attack, and how does it show that it does? The chapter states the question, gives the working thesis in five parts and says what would show it wrong, introduces the five stages of the loop and the independence principle, explains why the question is a European one in 2026 and 2027, sets the rules the book keeps and introduces the two organisations that run through it. It concerns all five stages by name: P1 Target, P2 Emulate, P3 Observe, P4 Improve and P5 Verify. Chapter 4 defines them; this chapter only introduces them, so that a reader can decide how to read the rest.
Two organisations emulate the same adversary technique on the same Thursday night. The technique is T1087.002, discovery of domain accounts, a discovery step that commonly follows a first foothold and that does little damage by itself (17, MITRE, n.d.). The organisations and the two outcomes below are fictional and illustrative; the book returns to both throughout.
At Nordvik Region, a regional public authority, the technique is run by a contracted tester, Elin Berglund, in the Region's identity-provider test tenant, as part of the autumn catalogue run under the call-off agreement NR-2026-071. The scenario is SCN-NR-0007, benign and reversible, and the expectation written before the run is that no detection fires, because the Region has declared this a gap. That is what happens. The tester's report records it, a person reads the report a few weeks later, and the finding enters the register. Nothing is wrong with this. What the Region can say afterwards is exact but narrow: on that night, in that tenant, the technique was run and not seen. Whether it would be seen now depends on what has changed since, and the next evidence arrives in the spring.
Primary topics explored
- A quarterly session and a continuous pipeline, two nights
- The loop in 2026
- The question the series had not asked of the loop
- The working thesis
- Five stages and five degrees
- Why Europe, and why now
About AI Purple
AI Purple is Book 9 of The Transformed Architecture. It takes the loop between the red team and the blue team as its subject and asks what happens when AI sits on both sides of the table: the five stages of the loop (target, emulate, observe, improve, verify), rules of engagement and safe emulation, continuous emulation, the independence principle, coverage as a claim that needs evidence, the loop's own AI and how to defend it, operating models, decision rights, regulation, and the people involved, for European enterprises and public authorities.
It builds on the conclusions of Architecture as Code, AI Governance, AI Platform and Security, AI Red Team, AI Threat, The Transformed Security Architect, AI Boss and AI Blue.
Chief information security officers, heads of security operations, red-team leads, penetration testers, SOC managers, detection engineers, purple-team coordinators and incident commanders, security and AI architects, boards and management bodies, procurement leads, works councils and unions, data protection and audit functions, and public-sector leaders.
Gunnar Nordqvist
Conceived, directed and published the books of The Transformed Architecture.
Continue with the full chapter
Chapter 1: Introduction: The Purple Loop with AI in AI Purple gives the detailed explanations, practical examples and implementation patterns behind this summary.
This whitepaper belongs to “The Loop in Question” and is one of 33 drawn from the manuscript.