QUIETLY, without fanfare, but unmistakeably, Dick Cheney is rewriting the American Constitution. Nowhere in the 215-year-old document does it mention the position of Co-President. But that is what Mr Cheney, nominally President Bush’s No 2, has become.

The war with Iraq, in its planning, execution and aftermath, is the latest chapter in that rewriting, but perhaps the most graphic yet. If the drive to topple President Saddam Hussein is not the Vice-President’s baby alone, his claim of joint parentage is beyond dispute.

Never has a Vice-President played such a central role in an Administration, let alone in the policy that will decide its fate. If there were any lingering doubt about Mr Cheney’s influence, it was dispelled by the first photograph released last week of the White House at war.

Arranged around the Resolute desk in the Oval Office, a gift from Queen Victoria, three men compete for the attention of another. George Tenet, Director of the CIA, is seeking to persuade him. Mr Bush is hesitant, watching carefully. Andy Card, Mr Bush’s Chief of Staff, awaits his response.

It is clear that the grey, balding, slightly stooped man with his back to the camera is going to settle the point under discussion. Amid the explosive chaos of war, these are pivotal times for the taciturn Mr Cheney.

The symbolism of Mr Cheney’s anonymous turned back speaks volumes. The Vice-President has never been a leader like the flashier figures in the Administration whose careers have criss-crossed his own — Donald Rumsfeld, the Defence Secretary, and Colin Powell, the Secretary of State. But he has an uncanny knack, displayed repeatedly over the past 30 years, of wielding quiet but enormous influence from the shadows. Thirteen years ago, as Defence Secretary, Mr Cheney was among the most vociferous to urge a swift deployment of American troops in response to Saddam’s invasion of Kuwait. He did not exactly egg on the first President Bush, but he was well ahead of his uniformed colleagues in suggesting that the United States would have to use force.

Loyalty is a defining Cheney trait, and he has never since publicly allowed any frustrations at Saddam’s survival to discredit the President Bush Sr’s decision to halt the war after liberating Kuwait.

Paul Wolfowitz, the neo- conservative Deputy Defence Secretary, who has for years argued for targeting Saddam, highlights how the famously quiet Mr Cheney keeps his own counsel. Even Mr Wolfowitz, as politically close to the Cheney camp as it is possible to be, says that he cannot describe the evolution of the Vice-President’s thinking on Iraq “because he is so tight-lipped and careful, I still don’t know from the end of the last war what his positions were”.

But from the outset of the present Administration, he has pushed his view that Saddam presents one of the greatest strategic threats to the US.

An interview that Mr Cheney gave in May 2001, just five months into office and well before September 11, hints at how his influence ends up dictating US policy. Asked about the main threat levelled at the US, he mentioned North Korea, Iraq and Iran. Less than a year later, that trio had become Mr Bush’s infamous “axis of evil”. Mr Cheney did not write Mr Bush’s State of the Union address that produced the label, but in a sense, using his unparalleled access to the President, he already had.

Similarly, Mr Cheney’s role in the run-up to war with Iraq is one of subtle persistence. He was always convinced that taking America’s case to the United Nations was a red herring. But only once, in a speech in August, did he make his doubts known publicly, giving warning that there was “great danger” that the inspection process would provide false comfort that Saddam was somehow back in the box.

When Mr Bush went to the UN in September, initially it looked as if the multilateralism of General Powell and Tony Blair had won the day. But time has told quite clearly that, in warning all along that the US was prepared to act alone, it was a thin veneer of General Powell and Mr Blair that had been added to Mr Cheney’s policy.

In recent weeks and months, as Downing Street and the State Department strained to achieve a second resolution, Mr Cheney offered Mr Bush constant reminders that broad international support was not necessary.

Times Recommends

• Michael Jackson: Not the final chapter
• Indian Army spends10m rupees on golf buggies
• Brüno toned down for 15 rating