Well, I don't see such a war happen at all - at this point in time.
I assume you refer to the Sudeten-crisis with "at Munich" and "1938".
IF ... the "Stresa Front" would somehow exist in 1938, most likely there won't be a Munich conference at all, as the wallies would make clear their "stand" already before.
IF ... a Munich conference would still take place it would end in no agreement, public desaster for Hitler and ...
... in both cases
the September or - as it's called in english texts/wiki - the Oster conspiracy would kick in with Hitler toppled/arrested/killed and a militarily lead "Interims"-goverment most likely avoiding anything, that would trigger hostilities or being quick in offering negotiations.
And the wallies most likely would jump on the occasion of negotiations instead of hostilities.
Pls don't forget : it was not only Hitler but even morer Chamberlain and Daladier who were celebrated as "preservers of peace" on their return from the Munich conference IOTL..
In 1938 war was exxxtreeeemly unpopular in France, GB, US and almost everywhwere - beside in Hitlers head.