Crossing the Yalu

Estimating Chinese intervention in Korea, autumn 1950

SIMULATION OVERVIEW

In autumn 1950 the Korean War appeared nearly won. After the amphibious landing at Inchon in September, United Nations forces broke the North Korean army, recrossed the 38th parallel, and began driving north toward the Yalu River — the border with the People's Republic of China. The central question now facing the U.S. Intelligence Community is whether China will intervene to stop them, and if so at what scale and toward what objective. The reporting reaching Washington is abundant and contradictory: diplomatic signals, allied assessments, propaganda, and fragmentary indications of Chinese troop movements point in different directions, and Beijing's intentions are deliberately obscured. You are an all-source analytic team. Working only from the contemporaneous record in the document room, you must estimate whether China will intervene, at what scale, and toward what objective. The outcome is not known to you. Weigh the contradictory reporting and commit to a judgment and a confidence level you can defend.

Devil's AdvocacyBias Identification

SIM PARAMETERS

TRACK

National Security

ROUNDS

DURATION

1h 50m

TEAM MODEL

All teams, same materials

POSTURE

RETROSPECTIVE

AUDIENCE

Undergraduate and graduate students in intelligence studies and national security programs; the OSU INTSTDS 4195 Intelligence in Action course, and professional analytic tradecraft training.

LEARNING OBJECTIVES

Produce an estimative judgment about adversary intent and scale under genuine uncertainty, and assign a defensible confidence level.

Identify mirror imaging in an estimate and explain how projecting Washington's risk calculus onto Beijing led to the conclusion that intervention was irrational and therefore unlikely.

Distinguish overcentralization of decisionmaking (assuming Moscow controlled Beijing) and oversensitivity to consistency (treating China's prior restraint as predictive) as separate, named analytic errors.

Separate analytic failure from collection failure, and individual analytic error from systemic and structural factors such as politicization and stovepiping.

Recognize deception when absence of evidence is mistaken for evidence of absence, and treat non-detection as an intelligence gap rather than reassurance.

Confront their own Round 1 estimate honestly and assess whether they reproduced the historical biases under the same conditions.

HOW IT RUNS

Briefing

Participants receive a scenario overview and their team assignment. Facilitator sets context and opens the document room.

Document Review

Teams examine scenario documents in the shared document room. Each round releases new intelligence as the situation develops.

Analysis & Submission

Teams complete a structured analytic worksheet applying Devil's Advocacy and Bias Identification, then submit their assessment.

Stakeholder Response

An AI-driven decision-maker responds to each team's assessment, reflecting how a real principal would react to the analysis provided.

Debrief

Teams compare their analysis against an expert benchmark. AI coaching surfaces analytical gaps, cognitive biases, and key insights.

WHO IT IS FOR

Intelligence Studies Programs

Ideal for upper-division or graduate courses in intelligence analysis, national security, or foreign policy. Builds practitioner skills through live simulation.

Professional Development

Used by agencies, think tanks, and defense contractors to train analysts in structured analytic techniques and collaborative assessment.

War Colleges & PME

Integrates with professional military education curricula focused on strategic intelligence and decision support.

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