It may be the case that wars fuel the economy, but there's more to the story than that. While defense contractors and those companies tied to providing supplies for the war effort may benefit, the rest of the economic sector (i.e. healthcare, infrastructure, environmental, basically domestic aspects) suffer as a result of said war.
As the case right now with Iraq and Afghanistan, certain areas of the economy have prospered (Haliburton, defense contractors, Blackwater - now known as Xe - etc.) while others have faltered (the housing crash, the collapse of banks, people loosing jobs, etc.) and suffered as a result of the war.
Obama recently called for an additional 18,000 troops to be sent to Afghanistan. Which pisses me off. Bring them all home, including those on illegal, foreign bases (where we have no right to be in the first place), and end the wars. I don't want to fight anymore, and neither does the majority of the public. We want (green) jobs, we want to know our homes and money are safe, to have adequate health care, and we want a government that cares more about helping the people more than it does about lining the pockets of big businesses which support the war at the expense of the rest of the country.