On the morning of September 11, 2001, President Alejandro Toledo of Peru sat down to breakfast in Lima with the visiting American secretary of state, Colin Powell. He was going on and on about textile quotas when an American aide suddenly rushed in with a message ripped out of a notepad. Two aeroplanes had crashed into the World Trade Center.

Two is not an accident, Powell realised. The next note said it was two jets. Powell thought: I’ve got to go home.

On his plane, Powell found that he couldn’t talk to Washington because the communications system there was swamped. Of all the things he hated, being out of the action was at the top of the list. The next seven hours of isolation seemed like an eternity for the man who could have been commander-in-chief.

In 1995, Powell, two years retired from the army, had considered running for president. But Alma, his wife, had flatly told him that if he did she would leave him. “You will have to do it alone,” she said.

After George W Bush won the Republican nomination for the 2000 election, Powell signed on to help, but the campaign had to move heaven and earth to get him to appear at an event with the candidate. Karl Rove, Bush’s political strategist, detected a subtle subversive tendency, as if Powell were protecting his centrist credentials and political future at Bush’s expense.

Nevertheless, Powell became the almost certain choice for secretary of state. Within his inner circle, there was a strong sense that voters knew they were choosing a team that included Powell. When the Supreme Court declared Bush the winner by 537 votes in the Florida saga, Powell’s advisers were convinced that their boss had provided the margin of victory many, many times over.

In his first months as secretary of state Powell never really closed the personal loop with Bush. There existed a distance between these two otherwise affable men as if they were stalking each other from afar. Rove felt Powell was beyond political control.

Whenever Powell was too out-in-front on an issue and became the public face of the administration, the political and communications operations at the White House reined him in, kept him out of the limelight. He joked that he was being kept “in the icebox” to be used only when needed.

Only a week before September 11, Time magazine printed a cover story saying he was leaving shallow footprints on policy. This was a very effective hit by the White House, where certain officials had co-operated with Time’s writers to prove Powell was operating — sometimes desperately, often in isolation — at the edges of the administration.

Now, as Powell headed home to Washington, war was about to be launched against terrorism. Would the president listen to him or only to the hardliners in the administration? The skirmishing began at a series of war cabinet meetings, chaired by Bush, on the day after the terrorist attacks. Vice-president Dick Cheney and Donald Rumsfeld, the defence secretary, both raised the question of Iraq.

It was the opening shot in a continuing struggle for the president’s heart and mind that continues this weekend as United Nations inspectors search for evidence of Saddam Hussein’s weapons of mass destruction.

How close did Bush come to siding with the hawks, spurning diplomacy and launching a unilateral American war on Saddam? And what is in his mind now? Iraq carries lots of baggage. Before he was elected, Bush told Condoleezza Rice, his national security adviser, that he disagreed with those who thought his father, George Bush Sr, had ended the Gulf war against Saddam in 1991 too quickly.

At the time, Bush Sr, Cheney (who was his secretary of defence) and Powell (as chairman of the joint chiefs of staff) had all agreed to end the war after achieving the stated goal of the UN resolution authorising the conflict: evicting Saddam’s armies from Kuwait.