Then there's the execution of Jose Medellin in Texas. While I am unquestionably opposed to the death penalty, that isn't the issue here:
Medellin's appeal to the top court relates to the Vienna Convention, an international treaty the U.S. signed that gives detained foreigners the right to consular help from their government.
The International Court of Justice, known also as the World Court, has argued that never happened in the case of Medellin and some 50 other Mexicans on death row in the United States.
In short, the executed criminal was never given access to Mexican consular services, even though the United States had signed the Vienna Convention. The execution of this man sends a clear message to the world - if the US signed a treaty, it's only meaningful as long as the Americans think it's to their advantage.
Which, of course, comes back to the Guantanamo Bay fiasco, where the United States is imposing arbitrary "law" upon people captured in a war zone - "law" that is arguably well beyond the limits that the Geneva Conventions would allow for.
The message is clear, the United States no longer subscribes to the very International Law that it has agreed to. I can imagine that travelling abroad on an American passport just became a whole lot riskier in some areas of the world - even with the size of the American army considered ... as the Romans proved, you cannot garrison the entire world - and sooner or later, somebody is going to decide to "make a point".