> Do we have reason to believe that the government knew there were no WMDs?

Yes; many of the specific bases of support they pointed to had been debunked before they were publicized by, among others, UN weapons inspectors. While it's far from proof, that alone is reason to believe that they were knowingly fabricating their claims.

You are putting the burden on the wrong shoulders. Cheney et el claimed to have extensive proof, which was later shown to be made up. Then there were things which were debunked even before we started the campaign, such as the aluminum rods which were supposedly for a nuclear reactor.

They didn't know there were none. It's hard to be sure of a negative like that. They knew the chances were too slim to justify a war without a lot of embellishing.

The joke while I was in Iraq was "We know he has WMD's because we have the receipts from the Iran-Iraq war when we gave them to him."... but we mostly knew what and where they were, their lifespan, etc, and that for the most part, "there was no "there" there". A few older things that had been heavily degraded were found.

I'll never forget being handed the same picture C Powell showed at the briefing and told "this is what we are looking for", given how we found out later that was bullshit.

Iraq was for other reasons. WMD was just one piece of how it was "sold".