Because my grandfathers have fought in wars. My elder relatives have seen their city bombed and destroyed. Families in other countries have endured WAR. Not just their country's army, half way across the world, invading a country that had never committed an attack on American soil.
Go to Iraq, and you tell a family there, with a destroyed home and dead loved ones, that this is a "war". War involves everyone, and you're sitting there, peacefully replying to a post about it on a website. You know nothing of war, because this is not one.