The neoconservative hubris that the United States can and should reshape the world has been a casualty of the Iraq war, both substantively and politically.
The practical limitations on the ability of the United States to direct the destiny of other peoples and cultures, and the cost of such ambitions, have been exposed.
Nevertheless, the three leading Republican candidates for president in 2008 - Rudy Giuliani, John McCain and Mitt Romney - cling to some version of the neoconservative vision.
This gives Democrats the chance to forge a new direction and consensus on foreign policy. However, if Barack Obama's speech last week to the Chicago Council on Global Affairs is illustrative, and it probably is, they aren't really up to the task.
The foreign policy challenge for the United States is figuring out how to operate in a world less and less interested in U.S. leadership.
Europe already has an economy roughly as large as that of the United States. The major Asian-Pacific economies (Japan, China, South Korea, India, Australia and Taiwan) are now about three-quarters as large. So, while obviously still a very important market, the United States is no longer a dominant economic force.
The United States does still have the only military with truly global reach. However, this yields considerably less influence than it used to, particularly after Iraq.
For the most part, other global powers see the U.S. military as a force not so much to be feared, as to be harnessed for sanctioned international missions or in response to international calamities, such as tsunamis and earthquakes.
In his speech, Obama acknowledged that the willingness to accept U.S. leadership has waned. However, he seems to think that it is just because George Bush is such a boor.
With nice and skillful American diplomacy, he maintains, the United Nations can be effective, the countries of Europe will spend more on defense, and NATO can assume more of the military burden.
There's no objective basis for this belief. The U.N. is structurally dysfunctional and its members like it that way. No amount of skilled diplomacy by the U.S. is going to overcome the lack of domestic support for increased military spending in Europe.
And Afghanistan has demonstrated that, while NATO may be useful for peace-keeping missions, it is ineffective as a fighting force.
The harsh reality is that if there are tough things that have to be done in the world, the United States is not going to have much company or support in taking them on.
Bush believes that, to protect the country against terrorism, the United States has to be an active agent of democratic change around the world.
Obama seems to believe that, to protect the country against terrorism, the United States has to be an active agent helping to provide clean water, food, medicine, shelter and education around the world. He would increase foreign and developmental aid to $50 billion a year and establish a $2 billion "Global Education Fund."
The track record on foreign aid is abysmal. Countries with sound governance don't need it. It doesn't do any good in countries without sound governance. Nor is there any indication that it can lead to sound governance, a conceit Obama shares with Bush.
Obama says he supports a strong military, but apparently wants to turn it into a sort of international WPA. He quotes with great approbation a Djibouti U.S. base commander who said that "our mission is at least 95 percent civil affairs."
According to Obama, the United States "must lead the world, by deed and example."
The essence of Obama's foreign policy perspective, then, is this: If the United States tries hard enough to do good and be nice, the rest of the world will be impressed and grateful and accept U.S. leadership.
That's not the world as it really is.
Obama's delusion, widely shared by Democrats, isn't nearly as dangerous as the neoconservative delusion still being served up by the Republicans. It's still a delusion, nonetheless.