What did churchill claim could have prevented germany from taking the sudetenland? did he offer any evidence for this claim?

In his speech, he talked about a third alternative, he said if only British government were able to form alliances among countries against Germany and if they are able to strengthen air force and British Army, only then they could have prevented Germany from taking Sudetenland. He believed that Germany will continue to expand its territories eyeing in Western Europe and British territories are not exempted.