Agile has principles. The question is: when do you apply which one?
The IIBA Agile Extension maps agile principles to the three horizons, and the insight is simple but underused: not every agile principle is equally relevant at every point in the work.
"Defer commitment" is a Strategy Horizon principle. Locking decisions too early at the strategy level wastes effort when the problem isn't fully understood yet. "Deliver value continuously" is a Delivery Horizon principle — it only becomes actionable when you're building and shipping. "See the whole" applies across all three, but means something different depending on where you stand.
"Agile is best described as a mindset because the values and subsequent principles explain ideas and attitudes with which people approach a situation, but do not prescribe exactly what they do in those situations." — IIBA Agile Extension
This is the key tension. Agile gives you attitudes, not instructions. The horizons give you a frame for when those attitudes are most useful.
In practice, this means: a BA running a visioning session at the Strategy Horizon is applying different principles than a BA writing acceptance criteria for a sprint. Both are agile work. Neither should be confused with the other.
For AAC candidates: the exam frequently presents a scenario and asks which agile principle applies. Mapping principles to horizons gives you a reliable anchor for those questions.
Exam tip: Learn the five core principles from the Agile Extension — deliver value, iterate, collaborate, learn, and stay aligned — and practice mapping them to which horizon each serves most directly.