The Iranians, who waged a bloody eight-year war with Mr. Hussein, have no desire to see a strong Iraq emerge from the ashes of his regime, especially one that has ties with the United States.
So they have sought to influence its politics by funneling cash to Iraqi political factions, ordering assassinations and shipping arms to militants, some of which an Oct. 23, 2008, cable from Dubai warned might be disguised as medical supplies. The Saudis, who see Iran as the chief threat in the region, have used their satellite television stations and deep pockets to support Sunni groups. Syria, which Iraqi leaders have repeatedly complained to American diplomats is dominated by a Baathist regime sympathetic to the ousted Baathists in Iraq, has allowed insurgent fighters to sneak into Iraq. Even Turkey, which has good relations with the Iraqi government, has secretly financed nationalist and anti-Kurdish Sunni political parties.
This shouldn't be a surprise. Before the United States invaded Iraq, I'm not sure the general public that supported the invasion gave much to Iraq's context in the region's politics. Or, to the extent they did, they A) got mad at Turkey for not letting us use their territory as an invasion route and B) hoped the example of knocking over Saddam Hussein would scare other regimes into line.
It didn't work that way. We Americans aren't very good at understanding politics on the other side of the world, didn't really grasp how Iraq's neighbors might use our actions to try to strengthen themselves -- or, at least, forestall a similar reckoning by the United States. On domestic policy, conservatives are quite good (and even quite smart) about recognizing the "unintended consequences" of laws designed to make our lives better and safer. On foreign policy, though, many -- Bill Kristol being, perhaps, the most prominent example -- seem to assume the world will fall into place via overwhelming force and fiat of the United States. It's a good deal more complicated than that, and I expect we'll be dealing with the fallout from this for the rest of our lives.