For the United States Canada Mexico Trade Agreement (2018) (trade) give a brief synopsis of the purported purpose(s) and provisions of the treaty, if (and if so, when) it was adopted, how many current signatory countries are there to the treaty (and, if the U.S. is one), has the U.S. ratified the treaty (if so, when; if not, why not), have there been countries (including the U.S.) which have withdrawn ratification (including who, when, and, if available, why), what is/are the official language(s) for the treaty, if it is not in force either why it should or should not be adopted/ratified by the U.S.