with one exception

This is key, it doesn't take more than one location to hide bio weapons.

Starting a war because someone did not give access promptly to one site for inspection sounds rather harsh, doesn't it? That sounds more like a rationale and not like a reason.

Just being in the country doesn't mean that they were able to do any actual inspecting.

Hans Blix said himself, that "Iraq has on the whole cooperated rather well". Furthermore "access has been provided to all sites" and "with one exception it has been prompt." Source

On top of that, how do you know the citizens didn't support it?

These historical huge demonstrations of concerned citizens were a dead giveaway, weren't they?

Dont forget the UN

The united nations were far away from supporting the invasion of Iraq. This Guardian article explains the details.

and every other country in the world that invaded Iraq with the US,

While there were certain governments to support the invasions, the citizens of these countries did not.

not due to WMD's, but due to Saddam not allowing UN weapons inspectors in. Iraq was not a sovereign nation, it was part of a ceasefire agreement where they promised to allow weapons inspectors in, and when they refused, they were then subject to the consequences.

Which is another apparent falsehood on your side. There were UN weapons inspectors in Iraq until few days before the invasion. The "coalition of the willing" regularly denounced any Iraqi efforts to follow agreements. I remember very well the day when Iraq gave thousands of pages of protocols and archive data to the United Nations. The coalition did not even read anything of it before condemning the material as untrustworthy.