America changes through times of conflict, growth, or peace and cooperation?

What was a major failing of the united states government under the articles of confederation?

The picture below shows president richard nixon and the first lady standing before the great wall of china in 1972. they are smiling - as are the chinese with them. when this picture was shown on american television, americans were aware that it was a historic moment. what are two reasons why this moment was important for both china and the united states?

How many countries have signed the kyoto protocol?