President Wilson involved the US in Mexico’s affairs for three main reasons.
First, he did so for economic reasons. The US had major economic interests in Mexico and had had them for much of the time of rule of Porfirio Diaz, which began in the 1870s and ended in the early 1910s. The US was therefore concerned about the upheaval of the Mexican Revolution.
Second, he did so for idealistic reasons. Wilson was concerned at least to some extent with spreading democracy in the world. Diaz had essentially been a dictator and Wilson hoped that the Mexican Revolution would help to bring more democracy to that country. For this reason, he was inclined to give help to the more democratic elements in the Revolution.
Finally, there were reasons connected to national pride and image. Wilson could not tolerate certain actions taken by Mexico (or individual Mexicans) against the US. This led to such things as the Pershing-led hunt for Pancho Villa and the brief US occupation of Veracruz.
These were the most important factors in Wilson’s actions towards Mexico.
There are several reasons President Woodrow Wilson involved America in the affairs of Mexico. These reasons include:
Wilson was a committed Christian and proponent of the “New Freedom” philosophy that advocated for democracy and self determination. He also believed that America had a moral obligation to foster global democracy by helping people under oppressive rule in other countries attain democracy. Mexico at the time was undergoing persistent political upheaval under the rule of despot Huerta and his predecessors. Wilson was compelled to act.
b. Economic Interest
Many Americans lived in Mexico and their number is said to have been more than the sum of all other foreign nationals in Mexico. In fact, it is said that by the time of the upheavals, 50,000 Americans lived and owed property in Mexico. It is further estimated that Americans owned 43% of the land in Mexico. Under the reign of Diaz, Mexico became a haven for foreign investment; America’s investment in Mexico surpassed the investments by all other foreign nations combined. More specifically, America had invested over one billion dollars in infrastructure, mines and oil resources. The magnitude of America’s economic investment in Mexico played an important role in Wilson’s decision to involve America in Mexico's affairs.
c. Border Security
There were an escalating number of US-Mexican border incidents that led to a build up of tension between the two nations. For instance, Villa's attack on Columbus prompted President Wilson to respond by sending his forces into Mexico. Even though Wilson did not employ direct intervention to quell the border episodes, his government sought to maintain stability nonetheless.