I don't think you impeach someone because you disagree with them. That's what elections are for. Part of living in a civilized society is respecting the rule of law. Bush was a horrible President, but he didn't break the law or do anything meriting impeachment.
Falsifying evidence and starting a war based on lies?
It's not that simple. The Bush administration thought there were WMD in Iraq. They may have also overstated, lied and deceived about the intelligence. But, that's also complicated because the intelligence is largely secret. Ultimately, it's perhaps the biggest blunder ever by a President, but it's not a crime or deliberate malice or treason.
I don't think you impeach someone because you disagree with them. That's what elections are for. Part of living in a civilized society is respecting the rule of law. Bush was a horrible President, but he didn't break the law or do anything meriting impeachment.
Violating international law multiple times?
There's a few answers to that.
One, which international law are you taking about? The only arguable one is if you consider invading Iraq to be a war of aggression. It's a gray area, but I would say Iraq doesn't qualify because Iraq was guilty of genocide, crimes against humanity and various other things. Just because something is horrible doesn't mean it's illegal.
Two, the US Congress doesn't get to make ex post facto international law. That's unfair and outside their Constitutional role because foreign policy is under the executive branch.