I think chess can be likened far more succinctly to war than life. War is combat, chess is combat, life doesn't have to be combat.
There are comparisons though of course - eg. planning, caution, development and maneuvering but at the end of the day, chess is a fight, a contest. Life doesn't have to be this way (unless you live in a war torn nation or something I suppose :])
Life is very similar to it though. Even nations that don't face war, still have a majority of the people that have inner struggles. Like you said "planning, developing, being cautious, betting on your next move. Very similar, if you ask me.
Chess is life. This was said, if I don't mistake, by both Fischer and Tartakower.
For Fisher this was especially true because he did not actually do anything besides playing chess. It literally was his life. Don;t know about Tartakower.
As for me, there might be parallels between life and chess but they are by no means equal. There's definetely more to life than chess.
thats on of those questions that gets its answer when playing chess, not when thinking about it. i occurs to me al the time that something unique on the board is happening and it develops itself just in the same way as it develops in life. it has a cause, it has a goal, it has an ending. surprises happen, plans don't come out the way you want, there are many choiches but you don't know which to make and so on....
Has anyone noticed, Chess is a lot like life itself. There is constant change. You have your agressive people in life that want everything fast, and attack right off the get go in the opening, and then you have patient people in life, who take their time to build a strong counter defense. Maybe I'm just starting to lose my mind, because of playing chess too much. =)