Recent discussions of U.S. policy toward Iran have demonstrated a great deal of disagreement on the proper course of action.

Hard-liners advocate confrontation, up to and including military strikes to attempt to slow Iran’s nuclear program. Internationalists calmly explain that we can work diplomatically with our allies in order to persuade Iran to give up its nuclear ambitions and come to terms with a new Iraq.

But the Bush administration seems to have no coherent overarching Iran policy. This disarray is causing a host of problems that threaten to undermine our ability to get other countries to cooperate with our Iran policy.

It also keeps alive the possibility that this administration (or the next one) could stumble down to the wire and decide to push the Iran panic button, making rash policy choices that would have devastating consequences for U.S. interests.

Take, first, the issue of Iranian involvement in Iraq.

For months, the U.S. ambassador to Iraq, Zalmay Khalilzad, has pushed for engaging the Iranians on the Iraq issue. In December, he told Newsweek that he had been authorized by the president “to engage the Iranians” on the future of Iraq, acknowledging that this was “a departure and an adjustment.”

Mr. Khalilzad’s vision has borne fruit. Last week, Iranian foreign policy chief Ali Larijani — who is also Iran’s lead nuclear negotiator — responded by announcing that a team would be sent to Iraq to speak with the Americans about the situation there. The move toward talks indicates a degree of grudging realism on the part of both Mr. Khalilzad and the Iranians.

The forward-leaning posture of the administration seems to have at least been tempered by its experience in Iraq and the gravity of potential military action against Iran. A ground invasion is out of the question, but even targeted strikes at Iran’s nuclear facilities could have many unpalatable consequences, including even more chaos in Iraq, Hezbollah fully unleashed against Israel, significant civilian casualties and broad international opprobrium.

Even so, according to a well-placed administration intelligence source, the Bush administration has decided to move away from diplomacy with respect to Iran’s nuclear program. The trouble is, it hasn’t yet settled on what, exactly, the new approach will be.

This raises still more problems.

First, if Washington has given up on diplomacy on the nuclear issue, it is difficult to imagine the Iraq talks getting very far. (One mitigating factor is that Mr. Khalilzad, as the leading proponent of the talks, has a lot at stake in making sure they don’t implode immediately.)

Second, if the administration knows it’s finished trying diplomacy but doesn’t have another idea in mind, it will be exceedingly difficult to extract any measure of international cooperation.

The administration’s “trust us” approach is not likely to get very far with the U.N. Security Council. The United States has to have a policy in mind before it can ask others to come along. The trouble in this case may be that nothing that could rally consensus internationally is acceptable to the Bush administration.

But the larger problem is that there is no consensus as to what — from the U.S. side — would be on the table if Iran could indeed be persuaded to forgo its nuclear program. The first prong of the administration’s new national security strategy is to “champion aspirations for human dignity.” That certainly wouldn’t comport with cutting a deal with the mullahs.

Similarly, the decision to beef up funding intended to destabilize the Iranian regime from within, through radio broadcasts and propaganda, seems to put the administration on a course toward regime change; recall the Iraq Liberation Act of 1998, which set the rhetorical stage for the Iraq war.

In short, Washington’s Iran policy looks to be almost entirely ad hoc at a crucial time during which any strategy of diplomacy — let alone a move toward confrontation — would depend on a strong consensus built around a strong case. If the administration doesn’t move away from its existing policy of speaking loudly and not being able to find a stick, it may end up watching history unfold without any ability to shape it.