A few weeks ago, in a meeting of the Permanent Council of the Organization of American States, US Secretary of State Kerry declared that the Monroe Doctrine was no long "valid." Perhaps this cavalier dismissal of what has been a pillar of American foreign policy for 190 years is simply a recognition that Iran, Russia and China are penetrating Latin America in a wholesale fashion, with no noticeable reaction on the part of the US.
The case of China is the simplest and least threatening. Generally, China is simply tying up supplies of energy, minerals and food (especially soy) through trade agreements and investment in sources of supply. In so doing, however, it is rapidly becoming the main competitor to the US in the latter's own back yard. No one seems to care.