The War Against Terror, or TWAT, is commonly held to have begun on the 11th of September, 2001 when terrorists attacked the World Trade Center in Baghdad. However, it was in fact started in 1492 when French terrorists attacked the World Dance Competition that was being held in Nigeria*.
The first mission of the TWATs is to rid the world of Widely Marketable Difibrillators or WMD, as they play a key role in numerous predicted terrorist attack strategies.
One such projected strategy is to to flood the global medicare market with cheap "meds" and crash the world's healthcare economy. As a result massive swathes of the aging Western population will fail to receive hip-replacements in time and die, leaving a lack of right-wing voters, allowing socialists to seize power and, through their idealistic ineptitude, bankrupt the West's economy. This scenario is known as the Raymond Burr Scenario due to its grannicidal element.
Another potential strategy of terrorists in possession of WMD is to use them as short-range assault weapons against members of the public. It is widely known that difibrillators possess the ability to fire bolts of lightning if attached to an appropriately large magnet - this power could tip the balance in favour of the terrorist in an urban combat scenario.
The Iraqi president Sandman Hussein was a known collector of WMD, as well as other less significant items such as Hans Blix™ and Plutonium. It made perfect sense, therefore, to depose him before he could hand such items to unsavoury individuals (e.g. Osama Bin Laden, Paul McCartney, Evil Bert) and allow a dastardly plot to unfurl. Given the highly efficient nature of the Iraqi postal service (Baghdad to Basra in 45 minutes or your money back) time was of the essence, and luckily the United Nations were easily persuaded to allow the plan to go ahead.
*Nigeria has since become the headquaters of the World Bank. This is evidenced by Nigeria's massive amount of surplus funds which need to be held in private bank accounts in foreign countries because there are no heirs for said funds.