Except for the fact that unlike Sonny he would NEVER have allowed Michael to become involved ... I don't really know, others can speculate those details.

But if you are Vito Corleone and an attempt has been made on your life because you've refused on principle to cooperate in a narcotics deal...you don't just lie down and give everybody what they want so that you'll be left alone.

I don't think Vito came as far as he did, built up the empire he did...to bother to negotiate after having his life threatened. Even with the knowledge that he was protected by a NYC police captain...Vito would still have found a way to eliminate Solozzo and yes, taken his chances on a war.

Remember also that he had not figured out at this point that Barzini, not Tattaglia ... was behind everything.

Apple