It also informs as to why the Comedian goes off the deep end when he learns about Ozymandius's plan. It reminds him of pulling the trigger on Kennedy.

The thing I really like about putting the JFK Assassination front and center in Watchmen is that the logic that the Comedian's hypothetical conspirators would have used to justify their actions is the same sort of logic that Ozymandias uses to justify the destruction of New york.