Hitler wanted war. Reading "Mein Kampf" makes that abundantly clear. In fact, he was obsessed with it. Most european nations however were deeply disillusioned with war after the first World War and had no interest at all in another. Add in the global financial crisis, massive problems with unemployment in most of the western world, most of them wouldn't have gained anything by war. And there was the treaty of Versailles. Basically, the treaty of Versailles had split the world in haves and have-nots. Versailles changed the situation of many states in Europe and for some, not to their satisfaction. England and France were winners of Versailles. They got former german colonies, massive reparation payments from Germany and more or less were the superpowers in Europe and large parts of the world. Other countries, Italy for example, had fought on their side in the war, hoping for winnings. Italy wanted african colonies. They didn't get them. So these "have-nots" like Italy and Germany were dissatisfied with the outcome of Versailles and wanted to change the order of things in Europe. (The terms "haves" and "have-nots" actually come form an analysis by Lenin)

Hitler wanted to achieve that by war. He always planned the great campaign for the "Lebensraum" in the east. He knew that he wouldn't get this without fighting war for it. What he wanted was a "rehearsal" for his great war. In the conflict about the Sudetenland his aim was actually to fight a "small war" for it. What he didn't expect was the war-weariness of the other european states. He didn't expect them to go so far in their appeasement that they would rather ignore the settlements made at Versailles than go to war for them. They effectively betrayed their own stipulations.

So you were asking about "calling his bluff". That's precisely the thing. Hitler didn't bluff. He wanted war. Whereas he was a dictator who made massive propaganda efforts to ready the population of Germany for another war which he always planned, the other countries had massive internal problems and their population would've in all probability reacted with strike or even riots if their government had decided to go to war for a tiny country which was mostly inhabited by Germans anyway. It is not a question of military might or readiness, but a question of politics.

The same happens actually when Germany attacks Poland in 1939. With all of the guarantees England had given the polish government: It takes until 1940 for any real fighting to break out on the western front. And then it's because Germany takes the initiative and not because France and England start attacking Germany.

Another point you mention/ask for is "readiness": The first World War had changed conceptions about how war would be fought massively. Everybody knew by now that the defensive armaments were vastly more powerful than any offensive. Or so they thought. Germany was one of the only countries which built tanks on a large scale and invested heavily into their airforce. Much of the surprise about the German "blitzkrieg" in 1939 stems from the fact that everybody had assumed that defense would be vastly more important than offense. Hitler's total disregard of defense in favour of mobile units and the according tactics was a surprise for everybody. I tend to think that a war in 1938 for the Sudetenland if the Munich Agreement wouldn't have happened would've gone very similar to the attack on Poland in 1939.

Further reading: Sebastian Haffner - "the meaning of Hitler" is a great book, even if some of his theses are out of date by now. Alternatively Ian Kershaw.

EDIT: forgot a reference - corrected