Reuters, 4/23/2015
Mexico’s congress approved on Thursday a reform that lets some foreign agents carry arms inside the country, a significant change in a nation that has historically said the practice would violate its sovereignty.
Under the law, foreign customs and migration agents will be allowed to carry guns in previously established zones. Also, foreign leaders or heads of state will be able to enter Mexico with armed security details.
Officials say the presence of foreign agents in Mexico will speed up the joint inspection process and facilitate the flow of goods and people across borders. They also say foreign customs and migration agents at times need guns to guarantee their security given the problems of drug and human trafficking.
Mexico Institute 