The reasons why the United States provided loans for the Latin American countries after they gained independence from Spain were mostly of economic and political interests.
By providing loans to these newly formed nations, the United States tried to create a positive opinion by the people in these nations about them, as they would have thought that the United States are helping them to develop. The real reason why the loans were granted though was to make these nations economically dependent and connected with the United States, thus the United States to have big power over them. Also, because this is a region in the neighborhood of the United States, they wanted to make sure that they would have things under control, create good relations with these nations, and avoid any future problems.
The Roman Empire's fall was largely due to the army being spread too thin to defend the growing territory. The army could not recruit fast enough to secure the huge increases in territory. Also the relocation of men from their domestic lives within the city to the mobile army bases caused a lack of day to day workers within the city. The economy suffered as result.
These leaders were called xyz, because they never gave the Patriots their names. This was known as the xyz affair.