Well, Kosovo, Haiti and Somalia are UN missions, which lefties like you love. Haiti and Somalia, of course, have already been abandoned by the UN, who believe as you do. The US is trying to bring democracy to Afghanistan, but it will take a while, as there has been no organized government in that country for decades. That doesn't mean they are too stupid or inferior to democratize. Only liberals are that arrogant.
BTW, I guess you think the Japanese and Germans, two peoples with no history of democracy, were also too "inferior" to embrace democracy?
Japan also had a recent democratic tradition including an elected parliament in the 1920s and free press. Neither country, of course, had the same degree of religious and ethnic division as Iraq. The UN had little with the interventions in Kosovo and Haiti though (at least in Kosovo) it was given authority by both Clinton and Bush. The UN has no role at all (that I know of) in Somalia.
BTW, I am equally against UN rule as I am against a MacArthur-regency. I support a third altenrative: allowing the Iraqis to set up an interim coalition govenrment asap and then turning over authority to it.
As to "loving" the UN, I support U.S. withdrawal from that organization.