Unless they only wanted to show the extent of their power over other nations. A strong signal, I might add. It could also be in the interests of US government to see which countries they control fully, and which put up a fight.

I don't think so. To some of those countries the US is already 'the boy who cried wolf'.

If anything it will motivate latin american nations to work together on the issue. If they act together for Snowdon's safety, it's much harder for the US to bully any single nation that accepts him.