In the movie "Thirteen Days", it is referenced multiple times that the father of Kennedy was "the architect of Munich" and might damage the USA in a serious way if Kennedy Jr. does not allow an attack on the missiles stationed in Cuba by the Russians.

To what exactly is this referring?

I could not find any sources online that would tell me what exactly they mean.

Video of the statement in question:

https://www.youtube.com/watch?v=hEL45ffs2x4#t=1396