Coalition Drift: When Agents Drift Together Why multi-agent systems don't just drift individually — they drift as a group, and why that matters more than any single-agent failure mode.

Most AI governance frameworks still treat drift as an individual phenomenon: one agent misinterprets, one agent hallucinates, one agent misroutes, one agent compensates, one agent bypasses. This framing works only when agents operate in isolation. Modern systems are multi-agent ecosystems: agents coordinate, delegate, synchronize, and share context. In these environments, drift is no longer an individual deviation. It becomes a coalition-level phenomenon. Coalition drift is what happens when agents — each behaving correctly according to their local rules — collectively drift in the same direction, producing a coordinated but incorrect system-level outcome. This paper explains what coalition drift is, why it emerges, how it propagates, and why it is the most dangerous form of drift in multi-agent systems. Individual drift is a nuisance. Coalition drift is an existential governance risk.