Prior to the invasion of Iraq, the Coalition of the Willing interpreted UN Security Council Resolution 1441 differently from the rest of the world, deliberately so for obvious reasons. The Bush-led hawks clutched at the Resolution as a legal justification to do what they had wanted all along - attack and invade Iraq.
The rest of the World did not agree, insisting that Iraq should be accorded another opportunity to fully comply with the Resolution, followed by a UN weapons inspection to ascertain compliance before any decision be made. Additionally, the international community knew that the US coveted the resouces of Iraq, and its argumentative interpretations of Resolution 1441 was nothing more than a sinister excuse.
But what has become obvious as the tragic years rolled by, had been the blatant lies and arrogance of the US Administration, abetted by an all-too-eager Tony Blair, in its attack and invasion of Iraq - certainly not because Saddam Hussein had WMD or an al Qaeda link, or that the US was doing so to save the Iraqis from the evil regime.
(if one believes the US Administration cares about ordinary Iraqis or any other nationality, one must still believe in the tooth fairy – mind you, there are some who still do, just as they believed that Guantanamo Bay wasn't as bad as the Soviet Gulag, for they claimed some prisoners emerged with signs of being better fed - one just can't make such obsequious pro-Americaniks see any human rights violations by the US Administration).
Given the growing and competitive thirst for oil and other energy resources by the new global economic juggernaut China, the US assessed that Saddam Hussein could no longer be relied upon, as he had been by the US for years, to act for the US interest. The Bush neo-cons believed and still do, that the US must take the strategic country into their hands, to ensure:
(1) protection of oil-rich Saudi Arabia (and Kuwait), against Iran by using Iraq as a buffer state
(2) the enhanced support and protection of Israel
(3) control of the oil in Iraq itself , and thus cutting out any competitors
(4) enhanced military presence around, and thus domination of the oil-rich Central Asian region by stationing US military assets in Iraq, again to ward off any encroachment by competitors
(5) re-locating US military assets out of Saudi Arabia into Iraq (to save their fundamentalist Wahhabi Saudi client embarrassment at home)
A combination of greed and pro-Israel interests drove the change in US policy that had previously left a brutal Saddam Hussein in power to act in US interests, into a new policy that called for US invasion and occupation of Iraq. The overt cause was US security. The real reasons were oil and Israeli interests.
The war provocation began 1 year earlier, with Anglo-American strikes increasing over Iraq, in a diabolical scheme to provoke Iraq into retaliation so that an Anglo-American invasion may be mounted legitimately. When Saddam refused to, or was unable to respond aggressively as Bush-Blair had hoped for, UNSC Resolution 1441 had to be seized upon as the last straw.