WASHINGTON – Former US vice-president Dick Cheney, chief architect of the “war on terror” who helped lead the United States into the ill-fated Iraq war, has died at 84.

Mr Cheney – who served alongside Republican President George W. Bush for two terms between 2001 and 2009 – died late on Nov 3 “due to complications of pneumonia and cardiac and vascular disease”, his family said in a statement.

“His beloved wife of 61 years, Lynne, his daughters, Liz and Mary, and other family members were with him as he passed,” the family said.

Mr Cheney had been plagued by coronary problems nearly all his adult life, suffering five heart attacks from 1978 to 2010. He had worn a device to regulate his heartbeat since 2001.

Mr Cheney worked for nearly four decades in Washington.

He served as the youngest White House chief of staff under President Gerald Ford.

He represented Wyoming in the House of Representatives, where he worked with President Ronald Reagan, and then served as defence secretary under President George H.W. Bush.

He had been enjoying a lucrative corporate career as CEO of energy company Halliburton when the younger Mr Bush charged him with vetting potential vice-presidential nominees.

That search ended with Mr Cheney himself taking the oath of office as the world No. 2 to a new president who arrived in the Oval Office after a disputed election in 2000.

Mr Cheney was in the White House, with Mr Bush out of town, when terrorists attacked the US on Sept. 11, 2001.

He quickly took charge while the president was out.

“When the president came on the line, I told him that the Pentagon had been hit and urged him to stay away from Washington,” Mr Cheney recalled in his memoir, In My Time.

“The city was under attack, and the White House was a target. I understood that he didn’t want to appear to be on the run, but he shouldn’t be here until we knew more about what was going on,” he said.

‘Super-Cabinet official’

Mr. Cheney was an architect and executor of Mr Bush’s major initiatives: deploying military power to advance the cause of democracy abroad, and championing tax cuts and a robust economy at home.

He also sought to strengthen the powers of a presidency that, as he and Mr Bush saw it, had been unjustifiably restrained by Congress and the courts in the aftermath of the Vietnam War and the Watergate scandal.

As Mr Bush’s most trusted and valued adviser, Mr Cheney foraged at will over fields of international and domestic policy.

Like a super-Cabinet official with an unlimited portfolio, he used his authority to make the case for war, propose or kill legislation, recommend Supreme Court candidates, tip the balance for a tax cut, promote the interests of allies and parry opponents.

But it was the national security arena where he had the most profound impact.

As defence secretary, he helped engineer the Gulf war that successfully evicted Iraqi invaders from Kuwait in 1991, then took a leading role a decade later in responding to the terrorist attacks of Sept 11, 2001.

To prevent future attacks, he advocated aggressive policies, including warrantless surveillance, indefinite detention and brutal interrogation tactics, and he pushed for the invasion of Iraq to topple Saddam Hussein in 2003, completing the unfinished job of his previous stint in power but leading to years of bloody warfare.

Early in Mr Bush’s first term, many Democrats, and even some Republicans, questioned whether Mr Cheney was the real power behind an inexperienced president whose qualifications had been doubted.

Although Mr Bush eventually asserted his authority and Mr Cheney’s influence waned by the second term, the image of Mr Cheney as a Machiavellian father figure never fully faded.

Mr Bush himself acknowledged those perceptions in his 2010 memoir, Decision Points.

He wrote that Mr Cheney offered to step down from the 2004 ticket after becoming known as “the Darth Vader of the administration”.

Mr Bush said he considered the offer, noting that accepting it “would be one way to demonstrate that I was in charge”.

In the end, he kept Cheney on the ticket, citing his steadiness and loyalty.

Most recently, he startled Americans of both parties by announcing that he would vote for then Vice-President Kamala Harris, a Democrat, in the 2024 election, denouncing her Republican opponent, former president Donald J. Trump, as unfit for the Oval Office and a grave threat to American democracy.