Right now the US is dependent upon oil from a good friend of Iran in Venezuela, which might just dry up if the US attacks its partner, and by attacking the #2 oil producer in the world, the US could plunge into a deep recession, if not depression. The US cannot survive without cheap oil as we have squandered our money on wars rather than building new electric high speed rail systems etc., so they could survive with ox carts and camels long enough for us to be economically destroyed and incapable of war. GW Bush is leading the US to its own destruction.
UN to hold off on separate Afghan bombing probe for now (Reuters)
from the article: Revolutionary Guards: Iran can penetrate Israel's Merkava tanks