This is from USTR's fact sheet on the U.S. - China "phase one" trade agreement announced on Friday:
Dispute Resolution: The Dispute Resolution chapter sets forth an arrangement to ensure the effective implementation of the agreement and to allow the parties to resolve disputes in a fair and expeditious manner. This arrangement creates regular bilateral consultations at both the principal level and the working level. It also establishes strong procedures for addressing disputes related to the agreement and allows each party to take proportionate responsive actions that it deems appropriate.
Based on this explanation (and a White House conference call about the agreement), I think that what they have in mind is what I discussed here (and reflects the second paragraph of Section 8 of the draft framework of May 2018). If I'm right, the enforcement mechanism would work something like this. First, there would be consultations. If the consultations don't resolve the issue, each side can decide on its own whether there is a violation and what to do about it. Thus, it sounds like the determination of whether there is a violation would be unilateral, and the determination that the response is proportionate would be unilateral. If, for example, the U.S. believes China is not complying with the IP provisions, then the U.S. can impose tariffs in what it considers to be a proportionate amount. This is still a bit speculative, and I eagerly await the final text, but that's my sense of things at this moment.
As to the impact of all this, I'm not sure it will be an effective enforcement mechanism (the consultations are a good idea, of course). If China thinks it is in compliance but the U.S. does not, these unilateral tariffs probably won't induce China to take any action. If, on the other hand, there were a ruling by a neutral adjudicator that China is not in compliance, China might take some action. What we have here just looks like a process to restart the tariff war if one side is not happy with how things are turning out (which presumably could be done without any special process).
