Feb. 20 (UPI) -- The Association Agreement between the European Union and Mercosur -- Argentina, Brazil, Paraguay and Uruguay -- may prove to be one of the most consequential interregional accords of this decade. Or it may not survive its own ratification process. Both possibilities are now alive simultaneously. Signed in Asunción on Jan. 17, after 25 years of negotiations, the agreement binds two blocs representing more than 700 million people and bilateral trade that reached €111 billion ($