International comity is a doctrine of practice rather than a binding rule of law — courts extend it voluntarily out of respect for foreign sovereigns' legal systems. It commonly arises when a US court considers staying or abstaining from a case in favor of a parallel foreign proceeding, recognizing a foreign judgment, or deciding how much weight to give a foreign discovery-blocking statute under the Aerospatiale balancing factors.

Comity is discretionary and can be withheld: a court can decline to defer where the foreign proceeding lacked basic due process, the foreign judgment was obtained through fraud, or the foreign rule at issue is repugnant to the enforcing forum's public policy. This distinguishes comity from full faith and credit, which is a mandatory constitutional obligation between US states rather than a discretionary courtesy extended to foreign sovereigns.

Juricratic treats a comity-driven stay or dismissal as a discrete branch outcome with its own probability, similar to how a motion outcome is modeled, rather than as an assumed background condition — a cross-border matter's decision tree carries this risk explicitly so it isn't silently baked into an undifferentiated settlement-value number.

Comity arguments surface when a US court is asked to enjoin a parallel foreign proceeding, decide whether to recognize a foreign judgment, or determine how much deference to give a foreign regulatory or insolvency proceeding touching the same dispute.