"Or just the ones with oil? "

I can assume from your answer that the number is greater than 1.
I could guess that you also think that Iraq was legitimate threat to American security- but you unwilling to say so plainly.

As for the decision to invade Iraq or not- I leave that to the Commander in Chief to consider the merits doing this.
The current results seems to indicate Bush made a wise decision.

As for:
"No country has the right to invade another because it perceives it as a potential threat. A pre-emptive attack is only justified if the threat is certain and imminent and potentially devastating, and even that circumstance is as dangerous as it is unpredictable, as we have learned the hard way."

This is utter nonsense.
Did we have the right to invade Kuwait to kick out Saddam?
Why is bombing a country any improvement over invading- in terms of "international rights". Why do people such as Clinton and Obama support the idea of bombing a country?
Why did Clinton actually order Iraq to be bombed?

The issue with invasion is we put more America soldiers at risk, than compared to merely bombing certain targets.
So the issue of bombing vs invasion is a domestic policy decision- rather than a significant distinction in international law or international agreements.

Saddam could be considered by any sane person as a criminal, and a criminal has no right to run a country. Removing a criminal from power, is not a criminal act, instead of a decent act in accordance with international standards. And if international standards did not allow such acts, then the international standards are indecent and repugnant- and if that were actually to be the case, these international rules should not to be followed.

Of course there is no international law compelling states to take action against criminal rulers, and rulers conduct within a nation in regard to international law is given wide latitude, but there is no form of international protection, that protects a leader when violating international law.

Saddam clearly violated international law on numerous occasions- his invasion of Iran that resulted in uncounted millions of deaths was one example. But his invasion of Kuwait is what prompted the US and other nations to action against him.
The result of that war against Saddam was a cease fire agreement. Saddam violated that agreement on numerous occasions. And ultimately, it was his unwillingness to comply with that cease fire agreement which led to Iraq being invaded, Saddam being captured, and executed.