Scenario description
Assume the United States and China publicly confirm that a bilateral nuclear risk-reduction, nuclear-test transparency, or missile-test transparency mechanism has taken effect. The mechanism involves U.S. and Chinese defense, foreign-policy, energy, nuclear-security, or comparable agencies and includes an operational practice beyond a pledge to keep talking, such as designated crisis or technical contact points, scheduled working-level sessions, advance notice for ballistic-missile tests, shared launch-notification procedures, or a process for addressing allegations of very-low-yield or decoupled nuclear tests. Assume no formal limits on warheads, launchers, missiles, or nuclear-explosive testing are created unless official statements explicitly say so; any notice periods, data fields, verification procedures, participating offices, costs, and implementation dates not publicly reported by the cutoff remain unspecified.