I'm afraid you're taking a very simplistic stance here. There's a more than 200 page document, most of it covering why the investor-state clause can still be invoked. Simply put, Russia never intimated to any of the other parties that it wasn't going to ratify the treaty, which is seen as the basis for why they do have jurisdiction. Generally, provisional application exists until a government states that it intends not to ratify the treaty. The amount of time that had passed since the signing of the treaty with no intimation to that effect indicated that the Russian government intended to ratify the treaty still, and hence provisional applications should apply. If a country's lawmakers decide they don't want the agreement within a reasonable amount of time, the provisional applications cease having an effect.

Regardless,

Incorrect. Countries are legally bound by ISDS rules from the moment they agree to the treaty - BEFORE the ratification process. It's done through the magic of "Provisional Application."

Is not a counterargument to the point I was trying to make that laws before the treaty came into existence are exempt from ISDS clauses.

But suppose we don't ratify it. Suppose that once CETA is made public for ratification, Canadians or Europeans are opposed and decide not to ratify it. We're still bound by it for three years. The taxpayers - can still be sued if we pass or enforce any law in that time that harms investors.

Well, CETA has been made public already. The EU is going through the process of translating and getting legal opinions on how to implement it, and once that is all done it will be up to the parliaments to decide whether they want it or not. If they, within a reasonable amount of time, decide they don't want it then the provisional applications simply don't apply any more.