On one hand :

" U.S. President George W. Bush expressed "deep concerns" over religious freedom and human rights in China " - CNN

and on the other :

" The International Court of Justice in The Hague sided in 2004 with the Mexican government's argument that the United States had violated the 1963 Vienna Convention on Consular Relations by failing to inform the arrested Mexican nationals of their right to seek help from the Mexican Consulate.

(...)

But the court, a branch of the United Nations, has no power to enforce its rulings. A spokesman for Texas Gov. Rick Perry, a Republican, has said that "the world court has no standing in Texas." " -- Los Angeles Times

The USA - where the Union can sign an international treaty the States dismiss - should worry a bit more about their international commitments before giving lessons to the rest of the World. I think it'll be MUCH harder in the near future for US nationals emprisoned in Mexico to have access to a consulary representative... Action, reaction...