The Accession Protocols to the Washington Treaty for Finland and Sweden have so far been signed by 28 of 30 NATO members. Once all NATO member countries have notified the Government of the United States of America (the depository of the Washington Treaty) of their acceptance of the protocols to the North Atlantic Treaty on the accession of the potential new members, the Secretary General invites the new countries to accede to the Treaty.
My question is, Can a NATO member, once it has ratified the Accession Protocols for candidate members, withdraw or cancel that ratification before the Secretary General invites the new countries to accede to the Treaty?
The background to this question is: I am participating in a forecasting tournament. The question I am trying to answer is, "What is the probability that Finland and/or Sweden become members of NATO before 1 July 2023?". My answer largely depends on the actions of Hungary and Turkey. I am wondering, however, if I can rule out the withdrawal/cancellation of any ratifications that are already given.