The left hand doesn’t know what the right hand is doing. Used constantly in American organizations, and worth reading literally. It describes one body with parts that have lost contact — not two people who disagree, but a single organism no longer coordinated.
Dropped the ball
The most common American phrase for a task that failed because nobody passed it on. The ball was in motion, in a sequence, between people. The failure is located in the handoff rather than in the work.
Fell through the cracks
The passive is doing deliberate work. Nothing is said about who let it fall. What the phrase describes is a gap in the system rather than a fault in a person, and Americans use it as an explanation that does not assign blame while still naming a failure.
Working at cross purposes
Two people or teams both working hard, both competent, and producing less than nothing because neither knew what the other was doing. It is not a charge of laziness or incompetence. It is a charge that the information did not move.
Groupthink
Irving Janis coined the term in 1972, studying American foreign policy disasters including the Bay of Pigs. His argument was that cohesive groups suppress dissent in order to preserve agreement, and the suppression is usually invisible to everyone in the room.
An American psychologist named the failure mode in which a team stops exchanging information while believing it still is.