'I want to say clearly and most emphatically that the Mexican government and the Mexican people have no reason to accept unilateral decisions imposed by one government on another," its foreign minister Luis Videgaray said on Wednesday.
"We are not going to accept that, because we don't have to." Quite right. Mexico does not passively have to accept Donald Trump's mass expulsions of its citizens. And it has significant leverage.
US Secretary of State Rex Tillerson and Homeland Security boss John Kelly are currently in Mexico to discuss bilateral cooperation in this new era. They will be given short shrift.
Senior Mexican politicians and diplomats, reflecting the huge rage at Trump’s characterisation of its migrants as “bad hombres”, have suggested a number of approaches that range from mass actions in the US courts in defence of their citizens, to appeals to the UN for support.
One top former negotiator, Gustavo Mohar, also points out that while “Mexico is obliged to receive Mexicans, it has the right to demand accreditation that they are indeed Mexican.” That proof would pose significant problems for the US authorities.
And former foreign minister Jorge Castaneda argues that one option may be for Mexico simply to stop enforcing its southern border controls, toughened at US request, and to allow Central American migrants again to stream north unimpeded to the US border.
These days, contrary to Trump “facts”, illegal migration to the US from Mexico itself is a relatively minor problem and apprehensions of Mexican immigrants at the border are running at their lowest since the 1970s.
But last year, Mexico returned 143,057 Central American migrants to their countries of origin. Overall, Mexico stopped and sent back almost twice as many Central Americans as the United States did.
Nor is Mexico under any obligation to accept deported Central Americans as Trump intends. Multiple other forms of co-operation from criminal intelligence to trade may also be blighted.
Not only is Mexico not going to “pay for the wall”, but the new US administration is discovering that it takes two to tango. Diplomacy by edict does not work.