However, Britain, France and Russia had an agreement to protect Czechoslovakia. When Britain and France went to meet Hitler in Munich, they never contacted Russia about the meeting or invited them, so they were already planning on appeasing Hitler. Russia would have thrown a monkey wrench into the plan. In the end, that's one of the reasons why Russia ended up signing the non-aggression treaty with Germany. Chamberlain could have had a treaty with Britain and France, but he slow-walked it, because he disliked Stalin. Had Russia, France and Britain chosen to take military action to stop Hitler from taking Czechoslovakia, it's likely they would have succeeded, because Hitler did not have the military or weaponry to stop them.
In the end, that’s one of the reasons why Russia ended up signing the non-aggression treaty with Germany.
Also because Hitler gave Russia half of Poland, which Britain and France were unwilling to do.
The treaty that also divided Poland, Finland, Estonia, Latvia, Lithuania, and Romania into spheres of influence between the two totalitarian states.