“Fundamentally, we have no idea what is needed unless and until we get there on the ground.”

That was then-Deputy Defense Secretary Paul D. Wolfowitz three weeks before the Iraq war began a decade ago. He was digressing from his script on what he thought would be positive results from a military action while appearing before the House Budget Committee on Feb. 27, 2003.

Do nations learn from mistakes?

Today the United States is in deep debt, in part from the Iraq war, the continued fighting in Afghanistan and the general fight against terrorism. Then there’s the cost from the worst financial crisis since the Great Depression.

As the nation slowly recovers, the United States and its allies are trying to prevent Iran from developing nuclear weapons and trying to force North Korea to end its program, which perhaps already includes nuclear devices. There is also a push for the Obama White House to take a more active role in Syria to halt the killing and prevent radical Islamic elements from gaining control.

How much more do Obama policymakers — or those politicians pushing for military action — know about what would happen if the United States were to bomb or initiate military operations in Iran or North Korea, or supply weapons or create a free-fly zone for the Syrian opposition?

Any of those actions would, in effect, put the U.S. militarily “there on the ground.”

A decade ago the United States and it allies invaded Iraq because the Bush administration wanted to stop Saddam Hussein from building nuclear weapons, prevent the transfer of chemical or biological agents to terrorists, or end general support of terrorists, including al-Qaeda. Some officials just thought it was time to end the dictatorial regime. Take your pick.

Economic sanctions had not worked, and the Bush White House had convinced a majority of Americans that Saddam had ties to Osama bin Laden and the attacks of Sept. 11, 2001.

“The truth is that for reasons that have a lot to do with the U.S. government bureaucracy, we settled on the one issue that everyone could agree on, which was weapons of mass destruction as the core reason,” Wolfowitz said more than a year later about the justification for the war, according to a Pentagon transcript of an interview he gave to Vanity Fair.

The fact is neither Wolfowitz nor Bush nor other senior policymakers knew much about Iraq’s culture and domestic politics. The result was that they totally underestimated the task being undertaken, which meant the loss of 4,400 U.S. service personnel and 32,000 wounded.

What many forget is that Iraq and Afghanistan also mark the first U.S. wars in which a president, first Bush and now President Obama, has not sought a war tax. The result: nearly $2 trillion in war expenditures put on the nation’s credit card.

2003 to 2013: A wide-angle look at Iraq

Have those pushing for military action against Iran, North Korea or involvement in Syria mentioned asking taxpayers to support paying for such operations?

“There is a lot of money to pay for this that doesn’t have to be U.S. taxpayer money, and it starts with the assets of the Iraqi people. We are talking about a country that can really finance its own reconstruction and relatively soon,” Wolfowitz told the House Appropriations defense subcommittee on March 27, 2003, a week after the invasion began. He certainly was wrong about that.

What about the arguments before the invasion regarding a nuclear-armed Saddam? In his nationally televised speech Oct. 7, 2002, as the U.S. buildup to war was taking place, Bush painted Saddam’s Iraq as having chemical and biological weapons and was “reconstructing its nuclear weapons program.”

With nuclear weapons, Bush said, Saddam “would be in a position to dominate the Middle East. He would be in a position to threaten America. And Saddam Hussein would be in a position to pass nuclear technology to terrorists.”

Insert Iran’s supreme leader, Ayatollah Ali Khamenei, or President Mahmoud Ahmadinejad and you have the arguments being made for military action against the current Tehran regime.

In February 2003 Wolfowitz told the House Budget Committee, “Disarming Iraq and fighting the war on terror are not merely related; disarming Iraq’s arsenal of terror is a crucial part of winning the war on terror.”

By two years later, Bush introduced what became an oft-repeated slogan that the country must see Iraq “as the central front in our war on terror.”

Of course the war on terror goes on, and the argument for military action now sounds much like the argument of a decade ago: Doing something will aid the fight against terrorism.

I take heart that the Obama White House, and even U.S. military leaders, seem to have learned the lessons of Iraq and are cautious about being pushed into new foreign adventures.

When asked about Syria on Monday at the Center for Strategic and International Studies, Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, said, “As a student of that part of the world now for about the last 20 years, I think Syria poses the most complex set of issues that anyone could ever conceive, literally, in every facet.”

He noted humanitarian concerns, but added that over the past six months the questions about who makes up President Bashar al-Assad’s opposition have become “less clear in some ways.”

“We’re doing planning so that I can provide options, but again . . . I don’t think, at this point, I can see a military option that would create an understandable outcome. And until I do, it will be my advice to proceed cautiously.”

That response is evidence of hard lessons learned.

For previous columns, go to washingtonpost.com/fedpage.