“If you are on the wire diagram as an Al Qaeda operative, you can be targeted just for reading the newspaper in your living room. These guys are not in that position,” said one senior Defense official, speaking on condition of anonymity.  The official said there was debate within the administration about whether to become even more aggressive toward Iranians in Iraq. Already, the arrests of Iranians have caused tensions between American and Iraqi officials, as well as heightening the strains between Tehran and Washington. Meanwhile, some lawmakers have expressed concerns that the administration might even strike militarily into Iranian territory just as Congress considers resolutions denouncing Mr. Bush’s war strategy for Iraq.  “You have to balance it,” this official said. “While you want to take care of the situation, you don’t want to cause an international incident where you provoke Iran.”  The White House has not issued a presidential finding authorizing covert action against Iranians inside of Iraq or authorized any military actions inside Iran, officials said.  President Bush kicked off a campaign of escalated rhetoric against Iran during a televised address to the nation on Jan. 10. For months, officials from across the Bush administration have accused Iran of supplying Shiite militias with high-tech explosives and training them to carry out attacks with roadside bombs.  Administration officials have thus far provided little detailed public evidence to support these claims. Officials said that Zalmay Khalilzad, the American ambassador in Baghdad, is planning a news conference for Wednesday during which he will present a dossier of Iran’s efforts to fuel sectarian violence in Iraq.  Part of Mr. Khalilzad’s presentation, officials said, will be to show evidence found during a December raid on a compound of the Iranian-backed Supreme Council for the Islamic Revolution in Iraq, or Sciri.  The officials said that among the evidence that would be presented were photographs, documents and a color-coded wall map that were seized in the raid detailing which Sunni neighborhoods in Baghdad would be targets for attack.  Some leading Democrats, including the chairman of the Senate Foreign Relations Committee, Joseph R. Biden Jr., and the chairman of the Senate Intelligence Committee, John D. Rockefeller IV, have criticized the Bush administration for building a case against Iran when American intelligence agencies still have a murky understanding of Iran’s intentions in the Middle East.  Last week, Mr. Rockefeller said that the White House campaign was unnervingly similar to Bush administration rhetoric in the months before the Iraq war.  Some Middle East specialists point out that an effort to move against Iranian agents could backfire and prompt Iran to strike back against America troops.  “It’s going to be a bumpy road inside Iraq because it puts U.S. forces at risk and because Ahmadinejad will be more confrontational,” said Patrick Clawson, an Iran expert at the Washington Institute for Near East policy, referring to Iran’s president, Mahmoud Ahmadinejad.  Military commanders in Baghdad say they have documented a rise in the number of sophisticated roadside bombs using “shaped charges” — a type of weapon that officials believe are imported from Iran. Military statistics show that the number of coalition troops killed by these weapons jumped dramatically during the last four months of 2006.  It was late last year, officials in Washington said, that Mr. Bush signed off on a more aggressive military offensive inside Iraq to counter Iranian influence. Secretary of State Condoleezza Rice confirmed the policy change in an interview on Jan. 12. An article in The Washington Post on Friday reported new details about how the policy was being carried out, including some that the administration said were inaccurate, without elaborating.  One person briefed on the Bush administration strategy said officials in Washington believed that by giving assistance to radical Shiite militants in organizations like the Mahdi Army, Iran was hoping to split off hard-line elements within these organizations and make them more beholden to Tehran.  By moving against Iranians inside Iraq, the Bush administration hopes it can persuade them to stop their efforts to create rifts among Shiites and to provide aid in attacks against American troops, the person said, requesting anonymity because the briefing he had received was not intended to be made public.  “The Iranian government needs to know that whether it’s the Quds Force or any other kind of Iranian organization, we are not going to tolerate American soldiers being targeted in that fashion,” said R. Nicholas Burns, a top State Department official. He was referring to a section of the Iranian Revolutionary Guards Corps.  A version of this article appears in print on , on Page A8 of the New York edition with the headline: Bush Defends Moving Against Iranians Who Help Shiites Attack U.S.-Led Forces in Iraq. Order Reprints| Today's Paper|Subscribe
The president and his senior aides justified American actions against Iranian operatives inside Iraq as necessary to protect American troops and Iraqis.