When will the Iran war end? Tracing the Trump administration's timelines

From a lectern at the White House, US President Donald Trump offered his latest assessment on how long the US-Israeli war with Iran might last.

Speaking on Wednesday night in his first televised national address on the war since he launched it in late February, Trump said the US was on track to achieve its military objectives in Iran "shortly, very shortly".

Trump reminded Americans that the conflict had so far been shorter than years-long wars such as World War Two and the Vietnam War, then gave an updated timeline.

"Over the next two to three weeks, we're going to bring them back to the Stone Ages, where they belong," he said.

The remarks were far from the first time that Trump, or senior members of his administration, have volunteered a timeline.

When Trump announced the start of his operation on 28 February, he said it would proceed "as long as necessary to achieve our objective".

Since then, the president has oscillated between saying the US has already won the war and that the military campaign will continue for a number of weeks, usually ranging between two and six. The six-week mark of the war will fall on 11 April.

Analysts who spoke to the BBC said it was typical for a US president to offer a timeframe for a conflict in an attempt to win favour with the public - only to then shift their estimates.

But the approach of the Trump administration had been unique, one expert said.

US Defence Secretary Pete Hegseth has appeared to suggest that there could be a tactical advantage to the apparent fluidity.

Answering reporters' questions on Wednesday, he said: "Don't tell your enemy what you're willing to do or not do, and don't tell your enemy when you're willing to stop."

"(Trump) said four to six weeks, six to eight weeks, three," Hegseth said. "It could be any particular number, but we would never reveal precisely what it is, because our goal is to finish those objectives, and we're well on our way."

As the conflict has continued, others in Trump's administration have offered their own predictions for how long the war might last - at times seeming to contradict the president.

On 8 March, Hegseth told CBS News' 60 Minutes programme that the action seen so far was "only just the beginning". Less than 24 hours later the defence department echoed him in a social media post: "We have Only Just Begun to Fight."

Yet that same day, in a press conference in Florida, Trump said the US had already made "major strides" towards achieving its military goals in Iran. "And some people could say they're pretty well complete," he added.

Secretary of State Marco Rubio, meanwhile, has given comments of his own, often landing somewhere between Trump and Hegseth.

"We can see the finish line," Rubio told Fox News on Tuesday, the day before Trump's White House speech on Iran. "It's not today, it's not tomorrow, but it's coming."

Trump's is not the first US administration to face questions of this sort.

Sometimes the timelines given by the president at the time have been vague, and sometimes more specific. Few of the wars, if any, ended up working out as the commander-in-chief predicted.

An estimate will often shift as a conflict evolves in real time, explained Prof Eric Min, from the University of California, Los Angeles, who studies conflict resolution and diplomacy.

"It is a tricky endeavour to try to figure out how long wars will last," Min said.

In 1967, President Lyndon B Johnson said there was a "light at the end of the tunnel" for ending the Vietnam War. His vague rhetoric was meant to appease a nation increasingly opposed to the conflict.

The effort failed - the war lasted another eight years, and its unpopularity at home helped drive Johnson's decision not to seek a second term in office.

Decades later, President Bill Clinton suggested in 1999 that the Nato bombing campaign against Yugoslavia might be brief. The airstrikes lasted for more than two months, longer than many had anticipated.

Then there was President George W Bush's infamous "Mission Accomplished" speech aboard an aircraft carrier two months into the Iraq war. US troops didn't leave Iraq until 2011.

"Presidents have often offered timelines to buy time with the public" during wars, said Thomas Patterson, a historian at the Harvard Kennedy School, "and almost all of them underestimate the time."

Still, Trump's case with Iran stood out because of the number of times the president and his advisers have seemed to adjust the timeline and rationale for the war, said the experts who spoke to the BBC.

"The inconsistency of positions throughout the administration is pretty unique; there's not really a historical analogue that I can think of," Min said.

For its part, the White House denies any such claim - and Karoline Leavitt said last month that "President Trump and his entire team have consistently laid out clear objectives".

Trump's address to the nation on Wednesday was highly anticipated, because it appeared the president might make major news in his first primetime speech on the war.

Washington speculated that Trump could announce that he was sending ground troops into Iran, or even that he was winding down the war.

Instead, Trump spoke of another new timeframe.