Many people in the United States argue that the US government is so incompetent that it should never conduct wars abroad.
This is policy of isolationism.
As far as I can see, before 2001 Sep 11, the Bush Administration was planning to be more or less isolationist in this same manner. It was going to phrase its isolationism as a dislike of hypocrisy. For example, it was going to (and did) withdraw from a greenhouse gas reduction agreement that gave China a sharp increase in internationally permitted greenhouse gas emissions; it was going to speak out against those who accepted bribes from Saddam Hussein's government in Iraq.
However, the attacks on the US World Trade Center and the Pentagon caused the Bush administration to act differently. It realized, or became able to say publicly that it realized, that even if the US only goes into the world in a relatively small way, the world will come to the US. Hence, it changed policy. (Incidentally, it changed in a way that is congenial to major people in the Bush administration.)
The US is now conducting war abroad. The US government's best argument, one it has never made public, seems to agree that the US is incompetent, exactly as its domestic opposition says. Where the current Bush Administration differs is in saying that therefore the US should undertake a dramatic course of action, such as invading and successfully occupying Iraq. The goal is to persuade the rulers of other dictatorships that they will be safer if they impel their police, especially their secret police, to cooperate with the US.
Put another way, as far as I can see, in 2003 and early 2004, US policy is based on the traditional US left Liberal view that US foreign policy and foreign aid over the past generation has failed: the US failed to stop the growth of an Arab culture in which many young men feel humiliated and shamed. Worse, with this understanding comes the connected view that the past failure of US foreign policy has been so deep that it will take at least a generation to reverse the consequences.
Given this reasoning, the only actions a government can take to defend its country over the next 10 or 20 years is to become more fearsome.
An alternative thesis is that people can be deterred from violent actions by the threat of punishment. Thus a potential murderer will not kill anyone if he fears being executed as a consequence. However, this thesis failed the 2001 September 11 attacks: the attackers died in the action. They were not deterred by the threat of death.
The US domestic opposition has provided a policy prescription: to fund changes in schooling and upbringing for the long term, and, in the short run, to fund restraint mechanisms, such as police and prisons domestically, or armies internationally.
Over the next 10 or 20 years, this prescription implies the need for US military action abroad.
Over the past century, US isolationism has led to major US involvement only in foreign wars in which large portions of the US population gained the impression that the US was attacked first. For example, the `USS Maine' (a US battleship in a harbor in then Spanish Cuba) suffered an explosion prior to the Spanish-American war of 1898. A German submarine sunk the Lusitania in 1915 prior to US entry into World War I. In 1941, the Japanese attacked Pearl Harbor, which led to US entry into World War II. The US introduced large numbers of US troops into Vietnam after the US government claimed a US naval ship was attacked in Gulf of Tongkin.
US isolationism also meant that agencies of the US supported dictatorships in Central American, the coup against Allende in Chile, military dictators in Greece, and Saddam Hussein's war against the then new theocratic Iran. Some people on the left protested against these actions, but were never able to organize strongly. In any event, none of these involved major US action.
Now the US has many troops abroad and fighting: the action is major.
In US mythological terms, the humiliated, the shamed, the culturally forsaken are living in the equivalent of the late 19th century `Wild West'.
One question becomes who will be the `law west of Pecos'? Will a man like Wyatt Earp be appointed sheriff by a legitimate international government? Or will some single country act on its own? At the moment, one country is acting on its own. Will this continue?
A second question is is whether current US action abroad will succeed? Or will it fail like past US policies?