<P> As of 2009, 62% of illegal immigrants in the United States originate from Mexico, but by 2014, they made up 52% of illegal immigrants . Commonly those who enter the United States illegally are smuggled in by individuals referred to as "coyotes". In 2005, according to the World Bank, Mexico received US $18.1 billion in remittances from individuals in the United States . The number of illegal immigrants was at its highest in 2007, at 12.2 million, and has since dropped to 11.1 million in 2014 . In response to this and the trafficking of illegal drugs the United States has built a barrier on its border with Mexico . </P> <P> Mexico is a major source of drugs entering the United States . By the 1990s, 80%--90% of the cocaine smuggled into the United States arrived through Mexico . In February 1985, US Drug Enforcement Administration agent Enrique Camarena, nicknamed "Kiki", was kidnapped in Mexico, tortured and then murdered, in what was seen as an attempt by the Mexican drug cartels to intimidate the United States . After one - party rule ended in Mexico in 2000, the Mexican government increased its efforts to combat the all - powerful drug cartels . The United States sent aid to Mexico for this purpose through the Merida Initiative . As of November 2009, the U.S. has delivered about $214 million of the pledged $1.6 billion . </P> <P> On 24 August 2012, a United States embassy vehicle was fired upon by Mexican Federal Police agents, causing two individuals to be wounded . The incident occurred south of Mexico City, while the vehicle had two Americans and a Mexican Navy captain who were traveling to a Mexican naval installation; the area where the shooting occurred is close to Cuernavaca, which is inflicted by several criminal organizations . Twelve Mexican Federal Police agents were arrested for the shooting . The two Americans were later reported to be Central Intelligence Agency agents, who were investigating a kidnapping . In early October 2012, there was strong evidence that the two CIA agents were victims of a targeted assassination attempt, as the Mexican Federal Police agents may have been working for the Beltran Leyva Cartel; however, it is one of several lines of investigation being conducted by Mexican officials . </P> <P> The US is the largest source of illicit traffic of weapons to Mexico . Many of the traceable weapons come from American weapons markets and festivals that do not have regulations for the buyers, and there is a geographic coincidence between the supposed American origin of the firearms and the places where these weapons are seized: mainly in the Northern Mexican states . Most grenades and rocket - launchers are smuggled through Guatemalan borders from Central America . Firearms that make their way to Mexico come from the American civilian market . Most grenades and rocket - launchers are smuggled through Guatemalan borders, as leftovers from past central - American conflicts . However grenades are also smuggled from the US to Mexico . In an effort to control smuggling of firearms, the U.S. government is assisting Mexico with technology, equipment and training . Project Gunrunner was one such efforts between the U.S. and Mexico to collaborate in tracing Mexican guns which were manufactured in or imported legally to the U.S. </P>

How has mexico's political history differed from that of the united states