Earlier quoted context omitted.
There were two big reasons reasons the US went into Iraq. One was Saddam Hussein and WMD. Everyone believed that he had them, and it's a matter of fact that he had used them in the past. Though they were never found, it's not illogical to believe that he was simply able to move them elsewhere or destroy them before they were discovered. And taking out his regime would remove a large destabilizing factor in that part…
This was the narrative toed by the Bush administration and Fox News, but many Americans and the international community by and large did not agree.
Bush said he had clear evidence of WMD's in Iraq, that he showed this to Blair and Blair confirmed. I think it would be fair to say that most people would agree that Hussein wanted WMD's.
So I think it's fair to think that most Americans and most in the international community believed that Iraq had WMD's. The argument was mostly over whether an invasion was an appropriate response.
It was only "crazies" who believed both that Bush lied and that he was able to either snooker Blair or convince him to join in the lie.
Sometimes the crazies are right, though.