One major talking point out of the Bush White House early on in the war in Iraq was that George Bush was not going to be another Neville Chamberlain. "We would take out Iraq before it started a much larger war."
To a large degree Hitler, and Chamberlain's appeasement of him was the fundamental argument for invading Iraq. And the counter arguments did not challenge this basic reading of comparative history, but instead discussed how big of a threat Iraq was and could become. Bush got a free ride on the concept that preventative war was the correct answer if Iraq would become a large enough threat.
But lets look for a moment on how the U.S. and the "free world" responded to the threat of Russia at the end of WWII and through the cold war. What did we do?
To a large degree the same as Chamberlain did with Hitler. We told Stalin that any country he was in, he could keep. We asked for elections in Eastern Europe but we had no guarantees and both Churchill and Truman knew that they were turning those countries over to Russian domination.
In the case of Finland (neither had troops there) and Austria (both had troops there) we agreed to their being neutral. And both were effectively neutral for the length of the cold war. In Greece and Turkey(?) we provided massive assistance when Russia assisted native communist movements. And we both stationed troops in Europe and provided massive assistance via the Marshall Plan.
But all of these actions were to defend what "we" held at the end of WWII. None of this was to take back anything that Russia held. And our troops were not enough to stop a Russian invasion. They were merely enough that a Russian attack would force our participation because of how many American soldiers would be killed.
All of this was very similar to what England and France did for Poland after Chamberlain met with Hitler. The only significant difference was that England and France had no troops in Poland and that was because they couldn't move them there.
The big difference was that Hitler took a gamble that he could beat England, France, Russia, and then later on, America. Stalin declined to take that gamble. Either one of them could have decided different. It wasn't what we did, it was what they decided based on what they were facing.
Yet Truman, Acheson, etc are viewed as brilliant statesmen for containing Russia without resorting to war. And their actions saved the lives of tens of millions. Another war in Europe would have been horrifyingly brutal and would have further devastated all of Europe as well as Russia and possibly America.
So what is the difference? The difference is that Chamberlain misread the situation and consistently took the wrong action. Truman and others correctly read the situation and consistently took the best action.
To be like Neville Chamberlain is not to always look for "peace in our time" (which is admitidly a very good goal). I postulate that to be like Neville Chamberlain is to misread the situation, to then take the wrong steps time after time, and to have those missteps lead to a war.
On the flip side, to be like Harry Truman is to also look for a solution that does not require war (ie peace). But to do so where each step is appropriate, effective, and leads to a balance where we can avoid war and remain safe. Truman did not "solve" the problem of Russia. He contained it and gave us "peace in our time."
If you look at the abysmal failure of Chamberlain as how he strove for his goal, not that he preferred peace for war - then George Bush is our Neville Chamberlain. Because his steps have consistently lead us to the worst result.
And like Neville Chamberlain, George Bush's decisions have led us to a larger, longer, more horrific war with global fallout than was necessary. Both could have avoided large scale war by taking a different path (Chamberlain by invading the Ruhr when German troops first entered it). Bush will join Chamberlain in history of mistake after mistake leading a country to an unnecessary war.
George Bush is no Harry Truman. But he definitely is a Neville Chamberlain.