Iraq war: success or failure?

U.S. troops are being withdrawn from Iraq, although several thousand contractors will be left behind. It is a good time to ask whether the war was worth the costs in money and lives. Before the war, Saddam Hussein was an annoying enemy, but Iraq served as a counterbalance to Iran. Today the two countries are allies. One thing that I am not sure of is whether Western oil companies have more access to Iraqi oil, which the more cynical may say was the real reason for the war.