[Revenge of Sith]

"The proposed resolution is the only option we're offered and doing nothing is unthinkable."

The resolution didn't specifically mention Afghanistan, but everybody knew at the time that the Taliban government in Afghanistan was harboring al Qaida and the US was going to attack Afghanistan. However, the proposed resolution on Iraq was the only option Congress was offered in that instance, and Ron Paul gave a speech in Congress where he made clear he was against going to war against Saddam Hussein.

[OrthodoxPresbyterian]

Ron Paul certainly opposed an Invasion of Iraq without a Congressional Declaration of War; he made that clear in all his speeches.

How he would have voted if the Congress had considered and adequately debated a Constitutional Declaration of War as Ron Paul proposed? If the Congress had performed its Constitutional duty?

You don't know that, and I don't know that. What we know is that Ron Paul did introduce an alternative to the "Resolution", and that was to Constitutionally Declare War. How any GOP Representative would have voted on a Constitutional Declaration of War is but a phantom of your imagination, because Congress elected not to follow the Constitution as Ron Paul advocated.