AMERICAN and Iranian agreement to talk to each other on how to halt violence in Iraq is good news indeed.
There is certainly plenty for the two countries to talk about. President Bush himself has been making oblique charges that Iran is funneling weapons into Iraq.
Iran has considerable influence among Iraq's Shiites, not only the largest group there but also providing the bulk of the country's newly trained security forces. The difference between them carrying out a violent campaign against Iraq's Sunnis and Iran's pressing them to behave responsibly is day and night.
It is also good that the two countries have somehow made their way past sparring publicly about Iran's nuclear development. The sensitivity and importance of that issue has not been diminished by the agreement to talk about Iraq.
Starting with a subject on which there is some agreement, such as Iraq, may make it easier to move on to a broader agenda, including the touchier nuclear question.
President Bush's decision that the United States should sit down with the Iranians may be more important for what it says about the American side's thinking than Iran's. It can help relieve Americans' concerns that the Bush Administration has in the back of its mind some foolish intention to attack Iran as it attacked Iraq, or to give Israel a green light to do so.
Some of the signs regarding Iran have looked like the preparations that led up to the 2003 attack on Iraq.
Conservative think tanks, the American-Israel Public Affairs Committee, the offices of Vice President Dick Cheney and Secretary of Defense Donald Rumsfeld, and lobbyists have developed relationships with anti-Iranian regime exiles, including the Mujahideen-e Khalq (MEK), the Iranian version of Ahmad Chalabi's Iraqi National Congress.
Secretary of State Condoleezza Rice recently asked Congress for $85 million to fund a program run by the vice president's daughter, Elizabeth Cheney, to beam anti-regime radio and TV broadcasts to Iran.
Perhaps most important for the United States, the American decision to talk to Iran, and Iran's own positive approach to such discussions, may indicate that both countries understand a fundamental fact: eventually U.S. forces will leave Iraq. That means the other countries of the region, including Iran, will find themselves responsible for containing violence there.
That is not only useful understanding, it is also the road out for the United States.