WASHINGTON: President Donald Trump says a war with Iran would be short, with no exit strategy required -- echoing assumptions that have pulled US troops into protracted conflicts in countries including Iraq.

Trump is apparently referring to a potential air operation against Iran, saying there would be no "boots on the ground" -- a strategy that has been successful against some adversaries, but which still carries risks of dangerous escalation with well-armed Iran.

"Over-optimistic beliefs about relatively quick wars played a part in causing World War I, Vietnam, the Soviet invasion of Afghanistan, the US operation in Afghanistan, and of course Iraq," said Michael Mazarr, a senior political scientist at the RAND Corporation.

"Any argument that conflict with Iran would be quick and highly contained would reflect -- as the Iraq case did -- a powerful desire to believe that war can be fought on the cheap," he said.

"There are cases where limited strikes do resolve fairly quickly, as in the 1998 US Desert Fox attacks on Iraq," said Mazarr, referring to a multi-day operation targeting Saddam Hussein's forces.

"But there are many other cases where the assumption of quick and easy military operations proves disastrously wrong," he said.

When asked on Monday about an exit strategy if war breaks out with Iran, Trump replied: "You're not gonna need an exit strategy. I don't need exit strategies."

George W. Bush's administration lacked an effective exit strategy for Iraq in 2003, hoping it could quickly install a group of exiles to govern -- a plan that failed, with the country descending into years of bloodshed.

- No 'boots on the ground' -

On Tuesday, Trump said on the Fox Business Network that a war with Iran "wouldn't last very long, I can tell you that."

That echoes a remark by Bush's secretary of defense Donald Rumsfeld, who said in 2002 that war with Iraq might "last five days, or five weeks, or five months, but it certainly isn't going to last any longer than that."

In fact, US forces did not leave Iraq for more than eight years, fighting a war that killed around 4,500 American troops and cost tens of thousands of Iraqi lives.

Trump's comments may reflect some of his typical bravado, and his last-minute halt to air strikes last week indicates he could be wary of further escalation with Iran.

The US withdrew from a nuclear deal with Iran last year, imposing punishing sanctions, and relations have sharply deteriorated since.

Washington has blamed Iran for a series of attacks on tanker ships and Tehran shot down an American surveillance drone last week, raising fears of an unintended slide toward conflict that both sides have said they want to avoid.

Trump told the Fox Business Network he was "not talking boots on the ground" in Iran, meaning he would instead turn to air strikes or cyber attacks.

"I think the administration's gonna... talk loudly and wield a pretty small stick," said Michael Knights, a senior fellow at The Washington Institute.

- 'Disturbing' parallel -

If the US carries out strikes soon, it would be "a limited air operation that would target Revolutionary Guard naval forces and coastal defense batteries and that kind of stuff," though a major campaign against Iranian nuclear infrastructure could come later, he said.

Limited strikes would not "require a full response from the Iranians," Knights said.

That response would likely involve Iran trying to shoot down US aircraft, attempting to target US naval assets, carrying out attacks on Americans in Iraq, and targeting Gulf states if they played a role in the strikes, he said.

While the US could be aiming for a limited campaign, "misperception" poses a danger, said Mazarr.

"Iran has no way of knowing US air strikes will stop after a day, or two, or three. They know multiple US officials have spoken of the need for regime change. Why would they assume a campaign would be limited?" he said.

There is also a "disturbing" parallel between discussion over war with Iran and the debate in the run-up to the invasion of Iraq, Mazarr said.

There has been an "almost total lack of a serious public debate about what this war would entail or whether it is in US interests," he said.

"If America ends up in a major war with Iran tomorrow or next week or next month, Americans will only have a minimal idea of how the country got there, and basically no concept of what that war will entail for the country." —AFP