No matter how strong presence the U.S. has they have to learn a lesson from previous two wars (Iraq & Afghanistan) Both the decisions were a utter failure of the U.S. Intelligence Buros, yes Iran is far weaker in military terms but the amount of pain world would experience is simply beyond imagination. Those who favor war should think twice before going to war, neither you can exterminate Iran nor Iran can wipe out Israel from the globe but the consequential loss for the world community would be far greater. Please do keep sanctions working against them, one fine day they would knee down to the sanctions.
U.S. warns governments, bankers Iran sanctions still in place (Reuters)
from the article: Top U.S. official: Military strike on Iran was never 'off the table'