Decentralization on an international scale does not by definition negate the power of the US government to intervene. I can offer two very clear examples, both of which demonstrate the exercise of what might be best described as Imperial power: Panama and Switzerland.
In the case of Panama, when it was clear that Noriega was acting counter to the interests of the US drug warriors, US armed forces were unleashed and in short order the drug war returned to status quo. The operative interpretation still in use by the DEA is that bad actors who enable criminal activity in the US will be pursued everywhere in the world. This doctrine has gone far beyond the limits of the DEA’s purview since 9/11.
US laws changed dramatically in the aftermath of 9/11 and the full extent of the powers enabled by the Patriot Act (and associated laws) have still not been revealed. In the case of Switzerland, which had resisted opening its banks to foreign scrutiny for generations, the US threatened an economic war, similar to that exercised against Iceland to achieve the Wikileaks shutdown. This whole sphere of control was enabled in the interest of “tracing terrorist money sources.”
If the Mericuh can exercise power, it will. Living and doing business in the ANZAC countries, for example, offers little or no protection from US interests. Australia is more amenable to requests than New Zealand, but Mega & Kim Dotcom are just one example of the exercise of extra-territorial power in ways once thought unimaginable.