The main reason why policymakers in the Johnson administration wanted to continue U.S. involvement in Vietnam is because they wanted to justify the commitment of the US to the conflict--a commitment that had cost thousands of lives in an effort to contain communism.
I read 1989 instead of 1889 when I answered this question I'm really sorry about that
The assassination of Archduke Franz Ferdinand that lead to the devastating, destructive period known as WWI.
Because his owner had died.
