British airline attacks

The U.S. have just arrested 21 British citizens in London, England Thursday August. 10th. British citizens plan to blow up commercial airlines with explosive in hand carried."They were not yet sitting on an airplane," but were very close to traveling, the official said, calling that the plot was "the real deal". Because of this the U.S. president raised the airline treat level. What is the world coming to? Why is this still happening? It seems to me that the world is still not uniting as one but dispersing more everyday. People are not realizing that the world really is not becoming peaceful but hateful. You would think that after 9/11 peoples viewpoints would have changed.

"The U.S. government raised its threat warning to the highest level for commercial flights from Britain to the United States early Thursday in response to a terror plot disrupted in London. Terrorists had targeted United, American and Continental airlines, two U.S. counterterrorism" officials said.

Have the treat been entirely eliminated? From the experiences in the past I am not sure that it is.