I respect Hanson a great deal, but I think this is a false charge:
In summer 1990 the American ambassador to Iraq, April Glaspie, tried politely to talk sense to Saddam Hussein about rising tensions with Kuwait. At one point she reportedly explained that “the United States did not take a stand on Arab-Arab conflicts, such as Iraq’s border disagreement with Kuwait.” Saddam shortly invaded Kuwait and two Gulf wars followed in the next two decades. Apparently he counted on U.S. indifference or a weak response to a far-away in-house Arab vendetta.
This is not an appropriate example of appeasement.
Our ambassador said only what was normal policy--policy we repeat when it comes to the Japanese-Chinese dispute over the Senkaku Islands--we have no position on territorial disputes. (Although we now make it clear that force to settle the dispute is unacceptable and we'd stand with Japan over an attempt to use force to solve the dispute.)
Recall that the dispute in question in 1990 was over border land that Kuwait pumped oil from and which Iraq claimed was their oil since the oil patch crossed the border. Even though Kuwait pumped from their side, the oil could have been from the Iraqi side. Although if memory serves me, during the recently ended Iran-Iraq War, Kuwait sold oil pumped from there for Iraq to pay for the war with Iran.
Also, there were planned talks over the border dispute coming up. We were simply saying we weren't trying to side against Iraq in the question of where the border should be--not whether Kuwait should be Iraq's 19th province.
Further, we signaled our military presence with our own Navy deployment in what was a pretty standard--if small--signal of our interest (Ivory Justice, begun on July 24, 1990). Yet Saddam did not pay attention to our "stay out" signals." Perhaps we did not signal loudly enough, but we did not give Saddam a green light with a wink and a nod from our ambassador.
When you consider that even in 2003 that Saddam did not think Bush 43 would advance all the way to Baghdad and drive him from power even after we deployed to Kuwait 60 combat battalions of Army and Marine troops that were joined by 10 British battalions (plus supporting units), I think it is safe to assume that Saddam simply disregarded our actions and statements in 1990 and believed what he wanted to believe.
So no, our treatment of Saddam in 1990 was not an example of appeasement. We gave no green light. Saddam was fully capable of seeing green regardless of what we were doing and nobody in his inner circle would dare contradict him.