The Gulf War II started with "shock and awe" on March 20, 2003. Within a few weeks the US military forces crushed the Iraqi's resistance, toppled Saddam's statue and declared an initial victory on May 2, 2003.
The result of the military campaign wasn't a main issue in this war, as there was little doubt that the multibillion-dollar US military would crush any defense swiftly. The outcome of the battle was even more predictable when Iraq was forced to reveal its military intelligence and let the US spy-planes fly freely over the country. Considering the real targets and challenges of this war, however, it was a complete defeat for America.
From the international standpoint, the main concerns of the war have been (1) the justification of the war according to the international principles, and (2) whether or not military action could deliver stability and democracy to Iraq as promised by the US. On the other hand, according to Americans the main targets of the war were (1) to prevent the imminent threat of Iraq weapons of mass destruction, and (2) regime change (possibly to substitute a puppet government in Iraq and hence having more influence in the middle east and the OPEC).
The US failed at the first point in convincing the world, particularly the United Nations, to endorse or support the war. Americans started the war unilaterally (with symbolic support of some allies), claiming that it would deliver the American and international demands by little cost and time. But the second failure happened shortly after the occupation. There were no weapons of mass destruction, thus no imminent threat!
Still some hope remained for the Bush administration: to complete the regime change. By quickly stabilizing the occupied country the US could demonstrate the efficiency of its approach to replace corrupt governments using military power. However six months have passed from then, many more have been killed, and the occupied country is less stable than ever. Apparently, the US approach was unsuccessful on this aspect too.
In brief, the US has failed to deliver any of the American or international demands through this war. Return of Collin Powell to the (once called obsolete and redundant) United Nation to request international aid, was the declaration of this defeat. So far the position of the Security Council suggests that any international participation requires international management of Iraq situation. That means the US will have less influence in Iraq's future, in spite of investing many lives and billions of dollars.
Condoleeza Rice, the National Security Advisor of the United States, assured that the US policy would be to "forgive Russia, ignore Germany and punish France" for their antiwar stances. Now having the US in trap, it is up to the world to choose whether to forgive, ignore or punish America.