Sen. Barack Obama spoke in Iowa on Wednesday.
CLINTON, Iowa (CNN) - Democratic presidential contender Barack Obama warned the Bush administration against expanding the war in Iraq to neighboring Iran, telling an Iowa audience Wednesday that he hears "eerie echoes" of the rhetoric that led up to the invasion of Iraq.
"George Bush and Dick Cheney must hear loud and clear from the American people and the Congress: You do not have our support, and you do not have our authorization, to launch another war," he said.
The Illinois senator's comments came during a speech on the future of the 4-year-old war in Iraq, which he said has only bolstered Iranian influence.
Obama said the Islamic Republic poses a "grave challenge" to U.S. interests in the Middle East by refusing international demands to freeze its nuclear fuel program and supporting Shiite Muslim militant groups - "But we hear eerie echoes of the run-up to the war in Iraq in the way the president and vice president talk about Iran."
"They conflate Iran and al Qaeda, ignoring the violent schism that exists between Shia and Sunni militants," he said. "They issue veiled threats. They suggest the time for diplomacy and public pressure is running out, when we haven't even tried direct diplomacy."
There was no immediate response to Obama's remarks from the White House.
A U.S.-led army invaded Iraq in 2003 after months of Bush administration warnings that then-Iraqi leader Saddam Hussein was concealing stockpiles of chemical and biological weapons and efforts to build a nuclear bomb. But U.N. weapons inspectors found no sign of banned weapons before the invasion, and the CIA later concluded that Iraq had dismantled its weapons programs in the 1990s.The Bush administration now accuses Iran of arming Shiite Muslim militias that are attacking U.S. troops in Iraq, and of developing a clandestine nuclear weapons program. Gen. David Petraeus, the U.S. commander in Iraq, told CNN on Wednesday that there is "no doubt" that Iran is supplying advanced explosives that have been used against American troops.
U.S. forces have conducted two rounds of naval exercises in the Persian Gulf this year. Sen. Joseph Lieberman, I-Conn., questioned Tuesday whether Petraeus needs the authorization to strike targets in Iran "in order to protect America's troops in Iraq." And administration officials have refused to say whether they believe they have that authority now.
Obama said he would use "tough and sustained diplomacy backed by real pressure" to limit Iranian influence, reminding Tehran that it faces further isolation - "including much tighter sanctions" - if it continues to defy international demands regarding its nuclear programs and to support violent elements in Iraq.
"As we deliver this message, we will be stronger, not weaker, if we disengage from Iraq's civil war," he said.
Earlier, Obama told CNN that Congress needs to send President Bush a "clear message" that change is needed in Iraq. He said that unless Congress forces the president to accept a timetable for withdrawing American troops, "We are essentially engaging in a bunch of symbolic action there."
Senate Republicans have managed to block efforts to wind down the war, using filibuster tactics that require a 60-vote majority to move ahead. But in Iowa, Obama said U.S. troops should begin to withdraw immediately despite Bush's warnings that chaos would follow a premature American withdrawal.
"He warns of rising Iranian influence - but that has already taken place. He warns of growing terrorism - but that has already taken place. And he warns of huge movements of refugees and mass sectarian killing - but that has already taken place," Obama said.
"These are not the consequences of a future withdrawal, they are the reality of Iraq's present. They are a direct consequence of waging this war."
Obama also used Wednesday's speech to remind supporters that he opposed the now-unpopular Iraq war from the beginning - unlike his leading Democratic rivals, Sen. Hillary Clinton and former Sen. John Edwards, both of whom voted for the 2002 congressional resolution that authorized the invasion. Obama, who was elected to the U.S. Senate in 2004, was an Illinois state senator at the time.
And he discounted Petraeus' congressional testimony this week about reduced levels of violence since Bush ordered 30,000 additional troops to Iraq in January. Despite the reduction from levels earlier this year, "We are at the same levels of violence now that we were back in June of 2006," he said.
"The same people who told us that we would be greeted as liberators; about democracy spreading across the Middle East; about striking a decisive blow against terrorism; about an insurgency in its last throes - those same people are now trumpeting the uneven and precarious containment of brutal sectarian violence as if it validates all of their failed decisions," Obama said. "The bar for success is so low that it's almost buried in the sand."