Eduard Beneš had the great misfortune of watching his country get broken up by Hitler and the Western politicians who helped him to do it. He's one of the few political figures in The Rise and Fall of the Third Reich for whom Shirer has a lot of sympathy.
Shirer characterizes Beneš as a "remarkable intellectual" (3.12.7) who did the best he could've been expected to do when faced with the terrible position in which he found himself—and his country—in the summer and autumn of 1938. Having been abandoned by Britain and France, who seemed willing to give Czechoslovakia to Hitler if it meant averting another world war, Beneš declared that Czechoslovakia had been totally betrayed by the Western powers.
He was forced to resign in October 1938 and fled to England when he saw that his life was in danger.
After Hitler successfully bargained his way into annexing large territories of Czechoslovakia and got President Eduard Beneš to resign, Hácha stepped in "to be President of what remained of Czecho-Slovakia, which was now officially spelled with a hyphen" (3.12.373).
Shirer describes him as "a well-intentioned but weak and senile man of sixty-six" (3.12.373). Shirer emphasizes that weakness again in Chapter 13: Czechoslovakia Ceases to Exist, where he describes how Hitler bullied a "groveling" President Hácha into surrendering the remaining territories of "the Rump State of Czechoslovakia" to Nazi Germany (3.13.96-119).
In Shirer's words, it fell to Hácha to "sign his country's death warrant" (3.12.115).
A Sudeten German, Henlein was among the many who succumbed to the "virus of National Socialism," and in 1933 he founded the Sudeten German Party in Czechoslovakia (3.12.12). Together with Hitler and the Western politicians who were taken in by Hitler's lies, Henlein helped to orchestrate the German seizure of vast Czechoslovakian territories—and, ultimately, the break-up of the nation.